These creatures are so small, that millions of millions might be contained in an inch square. When viewed singly, or separated from one another, they are exceedingly transparent, and of a lovely green; but, like all other transparent bodies, when numbers of them are brought together they become opake, and lose their green colour in proportion as the quantity increases, till at last they appear entirely black.
Notwithstanding the extreme minuteness of these animalcula, they seem to be fond of society; for, on viewing for some time a parcel of them taken up at random, they will be seen to disperse themselves in a kind of regular order. If a multitude of them be put into a jar of water, they will form themselves into a regular body, and ascend slowly to the top, where, after they have remained some time exposed to the air, their green colour changes to a beautiful sky-blue. When they are weary of this situation, they form themselves into a kind of rope, which slowly descends as low as they intend.
A small quantity of the substance containing these creatures having been put into a jar of water, it so happened, that one part descended immediately to the bottom, the other continuing to float on the surface. After some time, each of these swarms of animalcula exhibited a disposition to change its quarters. Botharmies, therefore, set out at the same time, the one proceeding upwards, and the other downwards; so that after some hours journey they met in the middle. A desire of knowing how they would conduct themselves on this occasion, engaged the observer to watch them carefully; and to his surprize, he saw the army that was marching upwards open to the right and left, to make room for those that were descending. Thus without confusion or intermixture each held on its way, the ascending army marching in two columns to the top, and the other proceeding in one column to the bottom, as if each had been under the direction of wise leaders.
V. arcuatus, utraque extremitate æquali.Plate XXV.Fig. 16. Bow-shaped vibrio, both ends of an equal size.
The body resembles much the shape of the moon at the first quarter; it is of a green colour, and has generally from seven to ten globules disposed lengthwise; the smaller ones are of a very pale colour, a pale green vacuity may sometimes be seen in the middle: some little varieties may be observed amongst them, which are not easily to be described; it will be enough to have given the reader their general and distinguishing characteristics.
V. linearis compressus, antice quam postice angustior. Linear compressed vibrio, the fore-part narrower than the hind-part.
A round transparent animalculum, or rather a long crystalline membrane, the hind-part broader than the fore-part, the apex subtruncated, the base obtuse, no perceptible intestines; in the middle are two spherical vesicules, and a third towards the lower edge. It moves quickly backwards and forwards with an undulatorymotion; they seem to be joined in a very singular manner, and were found in great plenty in salt water that had been kept several days, till it became fetid.
V. linearis basi globuli, apice linea transversa. A linear vibrio, with a globule at the base, and transverse line at the apex.
This is a white pellucid animalculum, resembling the letter T, with a globule affixed to the base. It is in motion and at rest every moment alternately; in the former case, it resembles the letter V; in the latter, the letter T. They are found plentifully in spring water.
V. linearis, colli, apice obtuso, cauda setacea. Linear vibrio, with a neck, the upper extremity obtuse, the lower one terminating in a setaceous tail.
This vibrio is of the shape of a sewing needle; the neck round, partly transparent, and marked in the middle with a red point; the trunk cylindrical, the edges obscure, the middle bright, and nearly of a triangular appearance, the tail resembling a fine bristle. A motion may be observed in the inside of this little creature. It does not bend the body when in motion.
V. sublinearis, colli, apice truncato atro, cauda setacea. Somewhat linear in its appearance, a well-marked neck, the apex truncated and open, the tail setaceous.
The body is very long and flexible, broadest towards the middle, which is also filled with grey molecules; the fore-part is drawn out into a straight transparent neck, the upper end of it thick and black. The motion of this animalculum seems to beproduced by the contraction and extension of the neck. It is found in salt water.
V. æqualis, caudæ apice tuberculato. Vibrio of an equal size throughout, the tail terminated by a little tubercle.
A round animalculum; the fore-part for about one-sixth of the whole length is transparent, and furnished with a sky-coloured alimentary tube; the lower part is bright and pointed, the middle full of small globules; a small knob terminates the tail. Found in an infusion made with salt water.
V. æqualis utrinque subacuminatus. This vibrio is of an equal size, rather pointed at both ends.
It is very similar to the vibrio anguillula,No. 71, differing principally in the shape of the ends, which in this are furnished with a long row of the most minute points. It does not adhere to objects by the pointed tail. The body is of a whitish colour, frequently convoluted, and drawn into different figures. Its motion is serpentine, sometimes to be met with perfectly straight and still, and is found in infusions of vegetables after some weeks standing.
V. filiformis, seta caudali geneculata. Filiform vibrio, the tail setaceous, and bending up nearly to form a right angle with the body.
In this vibrio, the mouth, the oesophagus, the molecules in the intestines, and the twisting of them, are very conspicuous. The tail is exceeding small, and bent so as to form a considerable angle with the body. It is found in river water.
V. æqualis, subrigidus. Vibrio of an equal size throughout, and somewhat hard.
This animalculum may be divided into four varieties, if not distinct species: namely, 1. Anguillula aceti. 2. Anguillula glutinis farinosi. 3. Anguillula aquæ dulcis; and 4. Anguillula aquæ marinæ. These varieties I shall first describe, together with the eels in blighted wheat, and then proceed with the rest of the vibrio.
Plate XI.Fig. 7.
Chaos redivivum, Linn. Syst. Nat. 1326.[124]Leeuwenhoeck Opera Omn. p. 3, n. 1, f, l, o. Joblot Observ. Micros. 1, p. 2, pl. 2. Hooke’s Micrograph, p. 216, pl. 25, fig. 3. Borelli Observ. Micros. 1, p. 7. Power’s Micros. Observ. p. 32. Adams Micrograph. Illustr. 4th edition, p. 125, pl. 38, fig. 197, A, B, C, D. Rozier Journal Physique, Mars 1775, Janv. & Mars 1776. Spallanzani Opusc. Phys. part 1, p. 83.
[124]Linnæus includes this and the paste eel under the same title:—Habitat in aceto et glutine bibliopegorum. He adds,—Reviviscit ex aqua per annos exsiccatum.Edit.
[124]Linnæus includes this and the paste eel under the same title:—Habitat in aceto et glutine bibliopegorum. He adds,—Reviviscit ex aqua per annos exsiccatum.Edit.
This eel is both oviparous and viviparous; it is filiform, but in other respects differs considerably from the paste eel. It is longer, not near so large, the tail is smaller and more tapering; it moves with much greater ease, and is more lively. In the tail of this eel we may observe in miniature, what may be seen on a much larger scale in that of the viper, viz. a small projection somewhat resembling a tongue, which occasionally appears as delineated in the figure ata b, and at other times adheres close tothe body. An alimentary duct may be easily discovered, but no other intestines can be discerned, without deranging altogether the organization of the animalculum. The pungent taste of vinegar was formerly attributed to these animalcula, an opinion which was soon exploded.
Plate XI.Fig. 6, 8, 9, and 10.
Chaos redivivum, Linn. Syst. Nat. 1326. Ledermüller Micros. Ergötzungen, p. 33, tab. 17. Baker Micros. made easy, p. 81. Ibid. Empl. for the Micros. p. 244, pl. 10, no. 8 and 9. Rozier Journal Physique, Mars 1775, Mars 1776. Adams Micrograph. Illustr. 4th edition, p. 125, pl. 38, fig. 179.
The eels in paste have been more distinguished than most other animalcula, as well on account of their many curious properties, as the various speculations and theories to which they have given rise. Four different species of eels may be found in paste; of the first, I shall now give a particular description. The body is filiform or like a thread, round, pellucid, replete with little grains in the middle, both extremities very pellucid and empty, the fore-part a little truncated, the hind-part terminating in a very short bristly point. It is the same of every age and size. To be certain of procuring this species of eels, boil some flower in water, to which you have added a few drops of vinegar; provide an earthen pot which has an hole at the bottom, and fill it with earth; then put the paste in a piece of coarse cloth, and bury it in this earth; the pot is to be exposed to the sun in the summer, or kept in a warm place in the winter; by these means in ten or twelve days you will very seldom fail of finding a large quantity of eels in the paste.
This eel, when at its full growth, is about one-tenth of an inch long, and rather less than one-hundredth of an inch in diameter. Fig. 6 represents one of these eels magnified about one-hundred and twenty times, only compressed so much between two plates, by means of an adjusting screw, as not only to prevent it from moving, but to lengthen and flatten it in a small degree. At the upper part there are two little moveable pieces or nipples,a a, between which an empty spacebis formed, that terminates in the mouth; the hinder-part is round, but there projects from it a short setaceous tailw; in the young eels the termination of the tail is not so abrupt as in the present specimen, but it finishes by a gradual diminution. There is probably a vent nearz, for the passage of the excrements; because when that part has been gently pressed, two or three jets of a very subtile substance have been observed to issue from it. If the pressure be increased, a small bladder will be forced out, a further compression bursts the bladder, and the intestines are forced through the opening.
A greater degree of magnifying power is necessary to obtain an exact idea of the viscera of these eels. Fig. 10 represents the alimentary duct further magnified, from its origin to the belly. It is shewn here as separated from the animal, which is easily effected; for nature, assisted by very little art, performs the operation. The oesophagus,b c; Fig. 6 and 10, at its origina a, is very small, but soon grows larger, as atc, and forms a kind of oblong bag,c d; the diameter of this increases till it comes tod, where it swells out as atd e f; it then grows smaller till it comes tog, when it again swells out atg k l. The partk lis the stomach. M. Becli has shewn, that the alimentary duct of many species of worms is formed of two bags, one of which is inclosed within the other. It is the same with this animalculum; the little vesselb c, that we have called the oesophagus, which is the origin of the bagc d, enters into the same bag, and preserves itsform within it till it comes tom, from whence it is prolonged in the form of a black linem n, which passes by the axis of the ducte, and apparently terminates itself at the beginning of the abdomenl. To this tube, near the center of the swellingg k l, are fixed two small transparent bodies; that end of these which is connected with the tube is round, the other end is pointed; these small pieces cannot be discerned in every position of the eel.
I shall now shew how this duct is to be forced out of the eel. The body, when compressed, generally bursts either at the head or tail, and always at that part which is least pressed; hence when the mass of fluids contained in the body is forced towards the anterior part, they meet with a resistance in passing from the abdomen to the duct already described; the abdomen, being forced by the fluids which are made to act against it, bursts at the upper end, and the fluids, striking against the neck, force it, with all its contents, out of the body, through an opening at the anterior part; on lessening the pressure, the intestine thus discharged will float in the water between the two plates of glass.
Not to enter into a detail of those parts which have been supposed by some writers to constitute the heart, &c. of these minute animalcula, it will be sufficient here to describe those in which motion may be discovered, and to leave the rest to future observations on the subject. The parts which may be seen in motion within these minute creatures are, 1. the small tube or duct, from its origin atm, to the two appendages; 2. these appendages themselves,h; 3. the remainder of the tube, from the appendages to the insertion at the ventriclek; 4. in the swellingg k l. The rest of this duct, from the beginning by the oesophagusb c, to the second swelling, has no motion. There is a variety in themotions of the first part of this duct, sometimes it dilates and contracts, at other times it has an oscillatory motion. It is difficult to gain a good view of the appendages; but when the position of the little creature is favourable, they seem to have a two-fold motion, by which the pointed ends approach to, and then separate from, each other, and another by which they move up and down. The partg k lmoves backwards and forwards alternately; the motion of each of these parts is independent of the rest. These are the principal parts, whose motion is connected with the life of the animal.
The other viscera that are contained in the body of the eel, and which may be observed by the aid of the microscope, are, the vessels which contain the food, those which are filled with a transparent substance, and the womb or ovary. The first form the abdomen and intestines; these are filled with a black substance, which prevents their being properly and clearly distinguished; these vessels, in their passage through the posterior part of the body, form an empty space, in which we may perceive that one side of the animalculum is occupied by the ovaryq q q, which runs fromjtou x; it is at these two extremities of the ovaries that the eggs begin to be formed, for the largest eggs are always to be found in the middle, and the smallest at the ends, as may be seen atj fandu x.
All the eels which bear eggs have two protuberances,y y, formed on the exterior part near the center of the ovary; it appears like a transparent semicircular membrane, but is really a kind of hernia or bag, in which one or two eggs may be sometimes seen; all the larger eels have this appendage, which also bears the marks of having been burst. Now, as the younger eels have not this appendage, nor any marks of a rupture, we mayreasonably conclude that it is from hence that the little eels issue from the parent.
In the latter part of the year, and during the winter, these eels are oviparous, and the young eels may be seen to proceed from the egg; at other times they are viviparous; six live eels have been seen at one time in the belly of the parent, twenty-two eggs have been counted in the ovary. Müller suspected that there was a difference of sex in some of these animalcula, but it was left to M. Roffredi to afford the proof, and it was only from a variety of repeated observations that he could allow himself to be convinced of this truth. He continued his researches upon the same subject on other microscopic eels, and has since been able to distinguish the sexual parts of the vinegar eels.
The second species of paste eel is oviparous. It is easily distinguished from the first kind by being much smaller; in Fig. 8, is exhibited a magnified view of this eel. The conformation of the alimentary duct and the intestines are in general nearly the same, though an intelligent observer will find out some specific differences. By the flexion of the intestinesc c c, a void space is left a little beyond the middle of the body, where the ovary,d d, is situated. There is no exterior protuberance near this ovary, as in the preceding one.
We meet with another eel in paste, which may with propriety be called the common eel. It is often to be found in grains placed in the earth, in which the germ is destroyed, in the roots and stems of farinaceous plants, in the tremella of Adanson, and in several species of conferva, as well as in several infusions. This eel, when at its full growth is rather longer than the common eel of blighted wheat; one of them is represented at Fig. 11.They are easily distinguished from the eels of blighted wheat, because they have no ranges of globules like it, by the two little protuberances which are near the middle of the body, and by the regular diminution of the tail. It is oviparous.
A very small species, represented at Fig. 9, may also be found in paste; they may be distinguished from the young eels of the larger sort by their vivacity and slenderness.
As the eels in paste are objects which are so often exhibited in the microscope, it will be proper, before we leave this subject, to inform the reader how he may procure the young eels from the parent animalcula; a discovery which was originally made by Mr. Sherwood, but more particularly pursued and described by Baker. Take up a very small quantity of paste where these eels abound on the point of a pin, or with a sharpened quill; lay it on a slip of glass, and dilute it well with water; by these means, many of them will become visible to the naked eye; then with the nib of a pen cut to a very fine point, and shaved so thin as to be extremely pliable, single out one of the largest eels, and insinuate the point of the pen underneath it; remove it into a very small drop of water, which you must have ready prepared on another slip of glass. When thus confined, it may easily be cut asunder transversely, by the help of a good eye and steady hand, with a lancet or sharp penknife; or if the eye be deficient, a hand-magnifier will enable almost any person to perform the operation. As soon as the parts are separated, apply your object to the microscope, and if the division has been made about the middle of the animal, several oval bodies of different sizes will be seen to issue forth. These are young anguillulæ of different degrees of maturity, each of which is coiled up, and included in its proper membrane, of so exquisite a fineness, as to be scarce discernible bythe greatest magnifier while it incloses the embryo animal. The largest and most forward break immediately through this delicate integument, unfold themselves, and wriggle about nimbly in the water; others get out, uncoil, and move about more slowly; and the least mature continue entirely without motion. The uterus or vessel that contains all these oval bodies is composed of many annula or ringlets, not unlike the aspera arteria of land animals, and it seems to be considerably elastic; for as soon as the operation is performed, the oval bodies are thrust out with some degree of violence by the spring or action of this bowel. An hundred or upwards of young ones have been seen to issue from one single eel, whereby the prodigious increase of them may be accounted for, as probably several such numerous generations are produced in a short time. Hereby we also learn that these creatures are not only like eels in shape, but are likewise viviparous, as eels are generally supposed to be.
Few experiments are to be found more entertaining, or in which there is so little risk of being disappointed; for they seem, like earth-worms, to be all prolific, and you may be sure of success, unless by accident you cut one that has already brought forth all its young, or make your trials when the paste has been kept a very long time, in which cases they have been found unfruitful.
Corculum vermiculo simile, Linn. Amæn. (Mund. Invis.) Anguille Vulgaire, Rozier Journal Physique, 1775. Mars, Nov. 1776. Ibid. Anguille du Bled Rachitique. Ibid. Anguille du Faux Ergot. Spallanz. Opusc. Phys. part 2, p. 354, pl. 5, fig. 10.
The body of this is exceedingly transparent, with no visible entrails, though a few transverse lines may be discovered on the body. It is sometimes, though rarely, furnished with a long row of little globules, and often with two small oval ones; the tail terminates in a point. Müller says he found these eels in the sediment which is formed by vegetables on the sides of vessels in which water had been kept for some time.
This, when pressed between two plates of glass, appears to be little more than a crystalline skin, with a kind of clay-coloured intestines. The fore-part of the body is truncated, the lower part drawn out to a fine point, the rest of the body is of an equal size throughout. The younger ones are filled with pellucid molecular intestines.
Plate XI.Fig. 4 and 5.
These animalcula were discovered by Needham, and described by him in a work entitled, New Microscopical Discoveries, and afterwards more fully treated upon by Baker. They are not lodged in those blighted, grains which are covered externally with a soot-like dust, whose inside is often also little more than a black powder; but abundance of ears may be observed in some fields of corn, which have grains that appear blackish, as if scorched: these, when opened, are found to contain a soft white substance, that when attentively examined looks like a congeriesof threads or fibres lying as close as possible to each other in a parallel direction, and much resembling the unripe down of some thistles. This fibrous matter does not discover any signs of life or motion, unless water be applied to it; the fibres then separate, and prove themselves to be living creatures.
These eels are in general of a large size, and may be seen with a common magnifying glass, being about one-thirtieth of an inch in length, and one-hundred and fortieth broad. Fig. 5 represents one of them magnified about one-hundred and twenty times; they are in general of a bright chesnut colour, the extremitya bis whiter and more transparent than the rest of the body. The endais rather round, the endcis pointed. A distinguishing mark of these little creatures is a row of transparent globules, which are placed at intervals through the whole length of the body, beginning atb, where the transparency of the fore-part ceases, and going on towards the extremityc. They are in diameter rather less than one-third of the body. Another peculiar mark is a small lunular spaced, near the middle of the body. This part is transparent, and is free from the coloured matter of the intestines; there is a neck in the intestines near this space, which confines them to one part of the body.
Great care should be taken by the observer, not to burst the skin of the eels in disengaging them from the grain, for they never break or burst of themselves; but if broke, visible intestines, filled with a black matter, rush out of the body, from which little black globules are disengaged; if the observation be made immediately after these globules proceed from the eel, they swim slowly about the water, though divested of any principle of internal motion; but if the eels that are broke be left long in the water, the same phænomena will take place, as in otheranimal and vegetable infusions. The want of due attention to these circumstances has been productive of many of the fanciful positions of Needham, which were deduced from ill-conducted experiments; and, consequently, when properly examined, are found to be in a great measure false.
M. Roffredi sowed some of the grains of this wheat, which sprang up; but the ear was either wholly or in a great measure spoiled, being filled with these eels. He also found them in other parts of the plant; in order to disengage them, the plant must be soaked in water, and then compressed a little. At first sight these eels seem to resemble the foregoing, but a more accurate inspection shews that they have neither the same curious disposition of the internal globules, nor the transparent place in the middle of the body. The intestinal bag leaves indeed in these an empty space, but it is of an undetermined form. The animalcula from the plant are much more lively than those which are procured from the dried grains.
The principal phænomena in this kind of blighted wheat is probably owing to these animalcula, who prevent the regular circulation of the sap. They increase in size in a certain proportion to the plant, so that at last they may be observed with great ease by the naked eye, being two-tenths of an inch long, and nearly one-tenth in diameter. Fig. 4 represents one of these magnified nearly in the same proportion as Fig. 5;a a a a, the ovary, which may be traced almost from the lower extremity to the middle of the body, where the body becomes so opake as to prevent its being seen any further. The eggs, when arrived at their full growth, are nearly of a cylindric shape, both ends rounded; towards the extremitybthere are two little protuberancesd d, through which the eggs are most probably extruded; these protuberances are not always visible. The eggs are formedof a fine transparent membrane; it covers the young eel, which is folded curiously therein; these eggs may be frequently found in the plant.
A most satisfactory view of these eels is obtained by examining them with the solar microscope; it affords one of the most surprizing and magnificent spectacles; two generations may be often seen, one, which draws near the allotted period of its existence, and another which only begins to enjoy the blessings of life: some arrived at their full growth, and others quite small. In some we may perceive the young animalcula in motion in the eggs, in others, no such motion can be observed; with a variety of other circumstances too tedious to enumerate, though they afford great pleasure to the spectator.
One of the most remarkable circumstances in these animalcula is the faculty they have of receiving again the powers of life, after having lost them for a considerable time; for instance, when some of these blighted grains, that have been preserved for many years, have been soaked in water for ten or twelve hours, living eels of this species have been found in it; if the water evaporate, or begin to fail, they cease to move, but, on a fresh application, will be again revived.[125]
[125]The property of revivification is not confined to this species, being common to other kinds of worms, and it is not improbable that the hydræ may possess the same faculty.Edit.
[125]The property of revivification is not confined to this species, being common to other kinds of worms, and it is not improbable that the hydræ may possess the same faculty.Edit.
It may be proper to notice here, that according to the observations of Roffredi, those eels which have done laying of eggs are incapable of being resuscitated upon being moistened; the same seems to be also the case with those that are very young; it is probable they must attain a certain age and degree of strength before they are endowed with this wonderful faculty.
In the month of August, 1743, a small parcel of blighted wheat was sent by Mr. Needham to Martin Folkes, Esq. President of the Royal Society, with an account of his then new discovery; which parcel the president was pleased to give to Mr. Baker, desiring him to examine it carefully. In order so to do, he cut open some of the grains that were become dry, took out the fibrous matter, and applied water to it on a slip of glass, but could discern no other motion than a separation of the fibres or threads, which separation he imputed wholly to an elasticity in the fibres; and perceiving no token of life, after watching them with due care, and repeating the experiment till he was weary, an account thereof was written to Needham, who, having by trials of his own, found out the cause of this bad success, advised him to steep the grains before he attempted to open them; on doing which he was very soon convinced of his veracity, and entertained with the pleasing sight of this wonderful phænomenon. At different times after this, Baker made experiments with grains of the same parcel, without being once disappointed. He soaked a couple of grains in water for the space of thirty-six hours, when, believing them sufficiently moistened, he cut one open, and applying some of the fibrous substance to the microscope in a drop of water, it separated immediately, and presented multitudes of the anguillulæ without the least motion or sign of life; but being taught by experience that they might notwithstanding possibly revive, he left them for about four hours, and then examining them again, found much the greatest number moving their extremities pretty briskly, and in an hour or two after they appeared as lively as these creatures usually are. Mr. Folkes and some other friends were witnesses of this experiment. We find an instance here that life may be suspended and seemingly destroyed; that by an exhalation of the fluids necessary to a living animal, the circulations may cease, all the organs and vessels of the body may be shrunk up, dried, and hardened; andyet, after a long while, life may begin anew to actuate the same body, and all the animal motions and faculties may be restored, merely by replenishing the organs and vessels with a fresh supply of fluid. Here is a proof that the animalcula in the grains of blighted wheat can endure having their bodies quite dried up for the space of four years together, without being thereby deprived of the property of resuscitation.
It appears plainly from the foregoing experiments, that when the blighted grains of wheat have been kept a long time, and the bodies of these animalcula are consequently become extremely dry, the rigidity of their minute vessels requires to be relaxed very gently, and by exceeding slow degrees; for we find that, on the application of water immediately to the bodies of these animalcula, when taken from the dry grains, they do not so certainly revive, as they do if the grains themselves be either buried in earth, or steeped in water for some time before they are taken out: the reason of which most probably is, that too sudden a relaxation bursts their delicate and tender organs, and thereby renders them incapable of being any more employed to perform the actions of life; and, indeed, there are always some dead ones amongst the living, whose bodies appear bursten, or lacerated, as well as others that lie extended and never come to life.
Some discretion is needful to adapt the time of continuing the grains in water or earth to the age and dryness of them; for if they be not opened before they have been too much or too long softened, the animalculum will not only seem dead, but will really be so. Of the two grains mentioned to have been four years old when put to soak, one was opened after it had lain thirty-six hours, and the event proved as already related; the other was suffered to lie for above a week, on opening which, all the anguillulæ near the husk were found dead, and seemingly in a decayed condition;but great numbers issued alive from the middle, and moved themselves briskly. Unless the husks be opened to let these creatures out after being steeped, they all inevitably perish; and when taken out and preserved in water, if the husks be left with them, they will die in a few days; but otherwise, continue alive in water for several months together; and, should the water evaporate, may be revived again by giving them a fresh supply.
V. ventricoso-ovatus, collo brevissimo. Ventricose oval vibrio, with a short neck.
This is one of the larger animalcula, of an egg-shape, pellucid, inflated, somewhat depressed at top; the apex is prolonged into a moveable crystalline neck, the belly is replete with pellucid molecules. It is not very common, though occasionally to be found among the lemnæ.
V. teres, antice angustatus truncatus, postice ventricosus. Round vibrio, the fore-part narrow and truncated, the lower ventricose.
It does not ill resemble a bottle in shape; the belly is replete with molecular intestines, the neck bright and clear, the top truncated; in some a pellucid point is visible at the bottom of the belly. It is in an unceasing, vehement, and vacillatory motion, the neck moving from one side to the other as fast as possible.
V. antice attenuatus, medio latiusculus, postice acutus. Vibrio with a small fore-part, the middle a little bigger, the hind-part acute.
This is a pellucid animalculum, in the middle are the intestines in the form of points; an alimentary pipe, which lessens graduallyin size, is also perceptible. The motion of it is quick, darting itself up and down in the water with great velocity. It is found in water just loosened from the frost, and seldom elsewhere.
V. crassus, postice acuminatus, collo subfalcato. Thick vibrio, sharpened at the end, the neck a little bent.
It is larger than most of the vibrios, and not unlike a bird in shape. The neck is round, shorter than the trunk, of an equal size throughout, and of a bright appearance, the apex obtuse. The trunk is thick, somewhat triangular, full of yellow molecules; the fore-part broad, the hinder-part acute, the motion slow.
V. elongatus linearis, anticem versus attenuatus, apice obtuso. Vibrio lengthened out almost to a line, small towards the fore-part, the apex obtuse.
The body linear, being a bright membranaceous thread, without any flexure; the hind-part somewhat thicker, round, and filled with molecules, excepting just at the end, where there is a small pellucid empty space. The apex is obtuse, and rather globose; it has a power of contracting and drawing in the filiform part.
V. oblongus, utroque fine attenuatus, collo cauda longiore. Oblong vibrio, both ends attenuated, the neck longer than the tail.
The trunk is oblong, opake, and filled with molecules. Both the fore and the hind-part is prolonged into a pellucid talkymembrane, which the animalculum has a power of retracting at pleasure. The tail is more acute than the neck. It is most generally found in salt water; a species of them have been found in river water, with a longer neck.
V. ventricosus, collo adunco. Corpulent vibrio, with a crooked neck.
This animalculum is little more than a most pellucid line, crooked at top, prominent in the middle, and sharp at the end; the fore-part, or neck, is equal in length to the rest of the body, and three times longer than the hind-part or tail; the intermediate part swelling out, is full of dark-coloured molecules and pellucid intestines. It is very small, and the most slothful of all those which move and advance their necks.
V. ellipticus, collo longo, tuberculo dorsali.Plate XXV.Fig. 27 and 29. Elliptical vibrio, with a long neck, and a little lump on the back.
It is between the vibrio proteus and vibrio falx, and is distinguished by the lumpb, Fig. 29, on the back, placed behind the neck; from this an even long neck,a, proceeds. The trunk,d, is elliptic, round, and without any lateral inequality; full of molecules, the hind-part,e, sharp and bright, the fore-part produced into a bending neck that is longer than the body; the apex even and whole, with blue canals passing between the marginal edges, occupying the whole length of the neck; in one of them a vehement descent of water to the beginning of the trunk is perceivable. The motion of the body is slow, that of the neck is more lively and flexuous, sometimes spiral. It is found in water where duck-weed grows.
V. ellipticus, collo longissimo, apice nodoso.Plate XXV.Fig. 28. Elliptical, with a very long neck, and a knob on the apex.
The form of the body is elliptical and ventricose, the hind-part somewhat sharp. It is membranaceous, dilatable, winding variously; the hind-part is sometimes replete with darkish molecules. The neck,d, is three or four times longer than the body, of an equal size throughout, except a small degree of thickness at the apex,f, very pellucid. The motion of its neck is very lively, that of the body slow. It is found in water that has been kept for a long time, and which has acquired a vegetable greenness.
V. gibbosus, postice obtusus, collo falcato. A gibbous vibrio, the hind-part obtuse, the neck crooked.
The body is pellucid, elliptical, the fore-part lessening into a little round bright neck, nearly of the same length as the trunk, the hind-part obtuse. The trunk itself is rather rounding or tending to the gibbous, and filled with very small molecules; there are also two bright globules, one within the hind extremity, the other in the middle of the body. The neck being immoveable, the motions of the animalculum somewhat resemble those of a scythe.
V. membranaceus, antice attenuatus, postice subacutus. Membranaceous vibrio, the fore-part small, the hinder part somewhat acute.
It seems to be an intermediate species between the preceding vibrio and the fasciola,No. 74; it is a thin membrane, constantly folded. The whole of it has a crystalline talky appearance, themiddle replete with grey particles of different sizes; it has all round a distinct bright margin; the apex of the neck is truncated, the tail obtuse.
Vermis inconspicuus, simplicissimus, pellucidus, complanatus, orbicularis vel ovatus. A simple, invisible, flat, pellucid, orbicular or oval worm.
C. orbiculare hyalinum. Orbicular bright cyclidium.
A very pellucid white animalculum, or orbicular skin, the edges a little darker than the rest. By the assistance of the compound microscope, some globular intestines of a very crystalline appearance are just perceptible. Its motion is slow and semicircular. It is found occasionally in an infusion of hay.
C. ellipticum crystallinum. Elliptic and crystalline cyclidium.
It is very pellucid, of a crystalline splendour, membranaceous and elliptical; a line may be perceived through the whole length of it, a point in the fore-part, the hinder-part getting darker. Its motion is swift, fluttering, and interrupted; probably both extremities are ciliated.
C. ovale crystallinum. Oval crystalline cyclidium.
This is one of the smallest animalcula. The body of an oval, or rather suborbicular shape, depressed, crystalline; two smallblue spaces may be discovered by the assistance of the microscope at the sides of this little creature.
C. ovatum, interaneis ægre conspicuis. Oval cyclidium, the intestines perceived with difficulty.
A pellucid oval body, with both ends plain, or an oval membrane, with a distinct well-defined edge; the intestines are so transparent that they can scarce be discerned, when it is empty; when full, they are of a green colour, and there are dark globules discoverable in the middle.
In plenty of water it moves swiftly in a circular and diagonal direction; whenever it moves slowly it seems to be taking in water, the intestines are then also in a violent commotion. Two of the smaller ones may often be perceived cohering to each other, and drawing one another by turns; nor are they separated by death, for they remain united even when the water is evaporated. Those who are not familiar with these kinds of observations, may easily mistake the shade in a single one for a junction of two, or the junction of two for a copulation, for they generate by division.
C. oblongiusculum, margine nigricans. Oblong cyclidium, with a black margin.
It is very small, pellucid, and flat. With a small magnifier, it may be mistaken for an enchelis.
C. ovale, antice mucronatum. An oval cyclidium, the fore-part pointed.
This is an oval, smooth, and very pellucid animalculum, with the fore-part running out into an obtuse point; with this it seems to feel and examine the bodies which it approaches. It is probably ciliated, though the hairs have not been discovered.
The intestines are filled with a blue liquor, forming in a tube, which, from the aperture to the middle of the body, is divided into two legs or branches; beyond the middle there are two little transverse blue lines. This colour sometimes vanishes, and then they seem to be composed of vesicles.
C. ovale, postice acuminatum. An oval cyclidium, the hind-part pointed.
The body is pellucid, depressed, the fore-part obtusely convex, the hind-part acute, the intestines vesicular, the fore and hind-part on each side dark. It resembles a grape-seed.
C. ovatum, postice acutum. Oval cyclidium, the hind-part acute.
This cyclidium is oval, flat, and bright, without any visible intestines, the hinder-part somewhat smaller than the fore-part; it has a tremulous kind of motion.
C. ovale convexum, subtus planum. An oval convex cyclidium, the bottom even. Trembley Polyp. 1, p. 282.
This is a gelatinous white animalculum, the bottom gibbous over the back, the extremities depressed and truncated, with one end sometimes apparently cloven into two; perhaps this is the aperture of the mouth. It is scarce ever seen but on the armsand the body of the hydra pallida, upon which it runs as if it had feet.
C. ovale, supra convexum, subtus cavum. Oval cyclidium, the upper part convex, the under part concave.
This is one of the larger species, the margin is pellucid, and the inner part contains a great number of black molecules.
Vermis inconspicuus, simplex, pellucidus, membranaceus, oblongus. An invisible, simple, membranaceous, flat, and pellucid worm.
P. compressum, versus anticem plicatum, postice acutum. Compressed paramæcium, oblong, folded towards the fore-part, the hinder-part acute.
This is rather a large animalculum, membranaceous, pellucid, and four times longer than it is broad; the fore-part obtuse, transparent, without intestines; the hind-part replete with molecules of various sizes; the fold, which goes from the middle to the apex is a striking characteristic of the species, forming a kind of triangular aperture, and giving it somewhat the appearance of a gimblet. Its motion is rectilinear, reeling or staggering, and generally vehement.
They are frequently found cohering lengthwise; the lateral edges of both bodies appear bright. They may also sometimesbe seen lying on one another alternately, at others, adhering by the middle. They will live many months in the same water without its being renewed. They are to be found in June in ditches where there is plenty of duck-weed.
P. cylindraceum, versus anticam plicatum, postice obtusum.Plate XXV.Fig. 26. Cylindrical paramæcium, folded towards the fore-part, the hinder-part obtuse.
It differs very little from the preceding, only the ends,a b, are more obtuse, and the margins filled with black globules. It is an inhabitant of salt water.
P. cylindraceum, postice incrassatum, utraque extremitate obtusum. Cylindrical paramæcium, the lower part thick, and both ends very obtuse.
An oblong, green, and gelatinous body, filled with molecules; the lower-part thick, the fore-part smaller, both ends obtuse, and may be seen to propagate by division. It is found in ditches.
P. depressum, intus bullis ovalibus.Plate XXV.Fig. 25. Depressed paramæcium, with large oval molecules withinside.
A membranaceous, oval, oblong animalculum, grey and pellucid, having many oval very pellucid corpuscles,a, dispersed about the body, and many black grains towardsb.
P. depressum, griseum, margine duplici.Plate XXV.Fig. 24. Depressed paramæcium, grey, with a double margin.
This is one of the largest of the class, flat, elliptical, every part filled with molecules, except in the lower end,b, where there is a pellucid vesicle; this animalculum is surrounded by a broad double margin; when expiring, a bright spiral intestine is observable.a, the apex;b, the vesicle;c, the spiral intestine.
Vermis inconspicuus, simplicissimus, pellucidus, complanatus, sinuatus. An invisible, very simple, pellucid, flat and crooked worm.
K. elongata, membranacea, antice curvata.
This animalculum resembles a long, narrow, and pellucid membrane, the hind-part obtuse, narrower, and curved towards the top; no intestines discoverable, only a ridge or fold going through the middle. Its motion is reeling or staggering, and very singular, moving to and fro on its edge, not on the flat side, as is usual with most microscopic animals. It is found in water, but is very seldom to be met with.
K. oblonga, dorso antico membranaceo hyalino. Oblong kolpoda, the back towards the fore-part bright and membranaceous.
The apex rather bent; the belly oval, convex and striated. It is found in fetid salt water.
K. oblonga, antice uncinata. Oblong, the fore-part hooked.
The fore-part is bent into a kind of hook; the hind-part is obtuse, and everywhere filled with black molecules. One of the edges from the fore-part to the middle, is often so blunted and dilated, that the rest of the body appears quite smooth, and that part thick and triangular. It has a slow and horizontal motion. It is to be found, though but seldom, in water where the lemnæ grow.
K. elongata, membranacea, apice attenuato, basi in angulum rectum producta. Long kolpoda, membranaceous, the apex attenuated, the base bent in a right angle to the body.
A large animalculum, long, and of a singular figure, depressed, membranaceous, flexible; one edge nearly straight, the other somewhat bent, filled with obscure molecules, and a few little bladders dispersed here and there; the apex bright and small, the base projecting like the human foot from the leg.
K. membranacea dilatata, antice angustata, altero margine incisa. Membranaceous, dilated kolpoda, the fore-part smaller than the hind-part, with a small incision at one side.
This animalculum is a dilated bright membrane; the apex an obtuse point, with a broad marked border running entirely round it; within the margin it is filled with grey molecules, a fleshy disc on one side, which terminates in a splendid little point on the other side the disc. It has a truncated appearance.
K. obovata depressa, altero margine retuso. Kolpoda nearly of an egg-shape, one edge turned back.
This animalculum appears to consist of two membranes; the upper side flattened, the lower convex; the apex is bent so as to form a kind of shoulder. It was found in salt water.
K. oblonga, subarcuata depressa, candida, antice acuminata, postice rotundata. Oblong, somewhat of a pear-shape, white, the fore-part pointed, the hind-part round.
It is very pellucid and white, the upper part rather bent, and terminating in a point, the lower part obtusely round; at the apex or mouth there is a little black pellucid vesicle; when a very great magnifying power is used, the body appears covered with long streaks; the lower extremity is furnished, like many other animalcula, with very small globules. It is to be found in salt water.
K. ovata, vertice acuto. Egg-shaped kolpoda, with an acute vertex.
It is of an oval shape, the vertex pointed, of a brilliant transparency, which renders the viscera visible; they consist of a number of round diaphanous vesicles.
K. mutabilis, antice uncinata, postice complicata.Plate XXV.Fig. 22. Changeable, with the fore-part like a hook, the hind-part folded up.
A most singular animalculum of the larger species; it has a dilated membrane, with the finest folds, which it varies and bends in a moment; the fore-part of the body to the middle is clear and bright, the hind-part variously folded in transverse elevated plaits, and full of molecules; the apex turned into a hook, the marginsinuous, and beneath the apex denticulated with three or four teeth; but in some which are more beautifully wrought, the edge is obtusely notched, and set with still smaller notches; in the hind-part there are twelve or more equal pellucid globules. It moves sometimes in a straight, at other times in a crooked line,a, the hooked apex;b, the denticulated margin;c, the series of globules;d, the folded part at bottom.
K. depressa, non plicatilis apice uncinato, margine antico ad medium, usque crenulato postice, dilatato acutiusculo. Depressed kolpoda, the apex turned in the form of a small hook; the margin of the fore-part notched from the top to the middle, the lower part swells out, then diminishes again into a short point. It has an elliptic mass in the middle, but is never folded like the preceding. It was found on the sea coast.
K. ovata, ventricosa, infra apicem incisa.Plate XXV.Fig. 23. Egg-shaped, ventricose, with an incision in the fore-part.
It is very pellucid, with a well-defined margin, filled with little bright vesicles, differing in size, and of no certain number. Its figure is commonly oval, the top bent into a kind of beak, seldom an acute one, sometimes oblong, but most usually obtuse. Its intestines are formed of from eight to twenty-four bright little vesicles, not conspicuous in such as are young. Some have supposed these to be animalcula which the kolpoda had swallowed, but Müller is of opinion that they are its offspring. In some only one crystalline vesicle occupies the middle of the body. It moves in general with great vivacity, and in all directions. When this creature is near death in consequence of the evaporation of the water, it protrudes its offspring with violence. It isfound in infusions of vegetables, and in fetid hay. In some few a transparent membranaceous substance may be perceived projecting beyond the beak, and resembling an exuvia; the same may also be observed in the enchelis and vibrio: it is, therefore, possible that these animalcula cast their skin, as is the case with many of the class of insects.ashews the cap or hood,bthe incision.
K. oblonga, infra apicem oblique incisa. Oblong kolpoda, with an oblique incision a little below the apex.
A very pellucid crystalline animalculum; it is furnished with several pellucid globules; there is a bending a little beneath the top, which in some positions is very distinctly seen, in others not. It was observed in an infusion of the sonchus arvensis.
K. ovalis depressa, infra apicem tantillum sinuata. Flat oval kolpoda, with a small degree of bending beneath the apex.
This is an oval, or rather an elliptical kolpoda, membranaceous and bright; flat on the upper side, and convex on the under; the fore-part is clear, and from the middle to the hinder-part it is filled with silver-like globules. It frequently stretches out the fore-part, and folds it in different positions.
K. crassa medio sinuata. This kolpoda is thick, and carved in the middle.
The body is yellow, thick, and rather opake; curved a little, in the middle, so as to have the appearance of a kidney; the whole body is filled with molecules. Its motion is quick, fluctuating, and interrupted. When the water in which it swims isabout to fail, it assumes an oval form, is compressed, and at last bursts. It is found in an infusion of hay, generally about thirteen hours after the infusion is made.
K. convexa, ovalis, apice in rostrum producta.Plate XXV.Fig. 20 and 21. Convex kolpoda, oval, the apex formed into a kind of beak.
The body is uniform and transparent, without any sensible inequality; the neck rather long and a little bent; it is of a pale colour, and furnished with obscure little globules. It propagates by division. Fig. 20 represents this animalculum; Fig. 21, the same dividing to form another;a, the fore-part;b, the hind-part;c, where it is dividing.
K. clavata, teres, apice dentata. Clavated kolpoda, round, the apex dentated.
This is a large animalculum, the body white, gelatinous, without any distinct viscera. It has a pellucid, bright, striated pustule on one side of the fore-part; the apex is distinguished by three or four teeth, the hinder-part is smaller than the fore-part, with an obtuse termination, which it can bend into a spiral form.
Vermis inconspicuus, simplicissimus, complanatus, angulatus. An invisible, simple, smooth, angular worm.
G. quadrangulare, pellucidum moleculis sedecim sphæricis.Plate XXV.Fig. 17. This gonium is quadrangular, pellucid, with sixteen spherical molecules.
These sixteen little oval bodies are nearly equal in size, of a greenish colour, pellucid, and set in a quadrangular membrane, like the jewels in the breast-plate of the high-priest, reflecting light on both sides. Its animality is evinced by its spontaneous motion, advancing alternately towards the right and left; these little bodies seem oval when in motion, round when at rest; the four interior ones are a little larger than the rest. It is found in pure water.
G. quadrangulare, opacum pulvillis quatuor. Quadrangular, opake, with four little pillows.
This appears like a little quadrangular membrane, plain on both sides; with a large magnifier it looks like a bolster, formed of three or four cylindric pillows, flattened or sunk here and there. Thus it appeared to Müller on the first examination; some days after all the sides were plain, without any convexity, and divided into little square spaces by lines crossing each other. It is found upon dunghills.
G. quadrangulare, albidum, medio correptum. Quadrangular gonium, white, sunk a little in the middle.
It is somewhat of a square shape, very minute, without any visible viscera, a little depressed in the middle. It is found in various infusions; in some positions it appears streaked.
G. rectangulum, dorso arcuato. This gonium is rectangular, the hind-part arched.
This differs but little from the preceding; the angle at the base is a right one, the larger vesicle is transparent, the rest green.
G. obtusangulum, postice arcuatum. Gonium with obtuse corners, the hind-part arched.
Much larger than the foregoing, the fore-part is a straight line, with which the sides form obtuse angles, the ends of the sides being united by a curved line; the internal molecules are of a dark green, there are two little bright vesicles in the middle; its motion is languid. It is found chiefly in pure water, and that but seldom.
Vermis simplicissimus, membranaceus, cavus. A very simple, hollow, membranaceous worm.
B. ventricosa, apice truncata. Ventricose bursaria, the top truncated.
An animalculum that is visible to the naked eye, white, oval, and truncated at the top, where there is a large aperture descending towards the base; most of them have four or five yellow eggs at the bottom. It moves itself at pleasure from right to left, and from left to right, ascending to the surface of the water in a right line, and sometimes rolling about while descending.
B. cymbæformis, antice labrata. Boat-shaped bursaria, the fore-part formed into a lip.
A pellucid crystalline animalculum, furnished with splendid globules of different sizes swimming about within it; the under-sideconvex, the upper side hollow, the fore-part forming a kind of lip.
B. utrinque laciniata, extremitatibus productis.Plate XXV.Fig. 19.
Bursaria with two small projecting wings, which give it somewhat of the appearance of a bird, and it moves something like a swallow. It is invisible to the naked eye, but by the microscope appears to be a pellucid hollow membrane; no intestines are visible.a, the head;b, the tail;c, one of the wings.
B. elliptica, marginibus inflexis.Plate XXV.Fig. 18. Elliptic bursaria with the edge bent in and out.
A crystalline membrane folded up, without any visible intestines, if we except a little congeries of points under one of the folds. It was found among duck-weed.
B. sphærica, medio pellucentissima. Spherical bursaria, very pellucid in the middle.
A subspheric hollow animalculum, the lower end furnished with black molecules of various sizes, the fore-part with obscure points, the rest entirely empty, and the middle very pellucid; it moves slowly from right to left.
Vermis inconspicuus, pellucidus, caudatus. An invisible pellucid worm with a tail.
C. rotundata, cauda acuminata. Round cercaria, with a sharp tail.
It has a white gelatinous body, without any traces of intestines; the fore-part somewhat globular, the hind-part round, long, and pointed; sometimes it appears a little compressed on each side. When swimming, the tail is in a continual vibration, like that of a tadpole. It seems very similar to the spermatic animalcula.
C. subovata, convexa, antice subacuta, cauda tereti. Somewhat of an oval shape, convex, the fore-part rather acute, the tail round.
It is a small animalculum, gelatinous, white, opake, and without any visible intestines; the upper part convex or gibbous; many of them were found in infusions of hay, as well as of other vegetables.
C. mutabilis, convexa, cauda lævi.Plate XXV.Fig. 31 and 32. Changeable convex cercaria, with a smooth tail.
This animalculum so often changes the form of its body, that it is not easy to describe it; it is sometimes spherical, sometimes like a long cylinder, at other times of an oval figure, white and gelatinous; the tail is filiform and flexible, the upper part vibrating vehemently; no visible viscera; a pellucid globule may be observed at the base, and two very small black points placed near the top atd, Fig. 32; whether they be eyes to the animalculum is not known. It was found in salt water.a, Fig. 31, the body;b, the tail.
C. mutabilis, subdepressa, cauda annulata.Plate XXV.Fig. 33, 34, and 35. Mutable cercaria, somewhat flattened, with an annulated tail.
This animalculum varies its form so much, that it might be mistaken for the proteus of Baker, though, in fact, it is totally different. The body sometimes appears of an oblong, sometimes of a triangular, and sometimes of a kidney shape. The tail is generally short, thick, and annulated, but sometimes long, flexible, cylindric, and without rings; vibrating, when stretched out, with so much velocity, that it appears as it were double. The intestines are not very distinct; a small pellucid globule, which Müller supposes to be its mouth, is observable at the apex; and two black points not easily discovered, he thinks are its eyes; sometimes it draws the tail entirely into the body. It walks slowly after taking three or four steps, and extends the tail, erecting it perpendicularly, shaking and bending it; in which state it very much resembles a leaf of the lemna. Fig. 33,a, the body rather spherical;b, the tail. Fig. 34,c, the triangular body;b, the tail. Fig. 35, the body extended;e e, the eyes;f f, the intestines;g, a large vesicle;h, a smaller one.