T. orbicularis, antice emarginata, altero latere crinita, postice setosa. Orbicular trichoda, the fore-part notched; one side furnished with hairs, the hinder-part with bristles.
T. depressa, mutabilis, flavescens, ciliis longis setisque pediformibus. Depressed trichoda, mutable, yellow, with long ciliated hairs, and feet tapering to a point.
The figure of the body is generally triangular; the apex formed into an obtuse beak, which the animalculum sometimes draws in, so that it appears quite round; the feet are four in number, one of them is longer than the rest; both feet and hairs are within the margin. It is found in water where duck-weed has been kept.
T. teres, ventricosa, rostro producta, postice setosa. Round ventricose trichoda, with a long neck, and the lower end set with bristles.
T. cymbiformis fulcata, antice et postice crinita.Plate XXVII.Fig. 17 and 18. Boat-shaped trichoda with furrows, the fore and hind-parts both hairy.
The body is oval; it resembles a boat as well in its motion as shape; the upper part is hollowed, the under part furrowed and convex; the stern round, with several hairs proceeding from it. It was found in salt water. Fig. 17,a, the head;b, the tail. Fig. 18,d, a pellucid bubble that is sometimes to be perceived.
T. ovalis, marginibus lucidis, antice et postice crinita.Plate XXVII.Fig. 19. Oval trichoda, with a lucid margin, both the fore and hind-part hairy.
It is about the size of the trichoda lynceus,No. 253, has an oval body, with a convex back, flat belly, and an incision in the margin of the fore-part, the edges of which incision appear to be in motion. Its intestines are pellucid and ill-defined. When it meets with any obstacles in swimming, it makes use of four small bristles, which are fixed to the under side, as feet.a, the hairs in the fore-part;b, the bristles at the hind-part;d, the back;e, two small projecting hairs;f, the substance to which the animalculum has affixed itself.
T. ovalis, marginibus obscuris, antice et subtus crinita, postice mutica. Oval trichoda, with an obscure margin, the fore-part covered with hairs on the under side, and the hinder-part beardless.
It does not differ considerably from the preceding, though Müller has pointed out some shades by which they may be discriminated.
Vermis inconspicuus corniculatus. An invisible worm with horns.
K. orbicularis membranacea, nasuta, corniculis in tota pagina. Membranaceous, orbicular kerona, with one projecting point, the upper surface covered with small horns. There are three rows of horns on the back, which nearly occupy the whole of it. It was found in river water.
K. subquadrata, rostro obtuso, disco corniculis micantibus. This species of kerona is rather square, and its disc furnished with shining horns. See Zool. Dan. prod. add. p. 281.
K. oblonga, antice punctis mucronatis nigris, postice pinnulis longitudinalibus instructa.Plate XXVII.Fig. 20.
It is an oblong membrane, pellucid, with four or five black points in the fore-part, which are continually changing their situation, thick set with small globules in the middle, among which four larger ones are sometimes perceived, these are probably eggs; in the middle space of the hind-part are some longitudinal strokes resembling bristles, which, however, do not seem to project beyond the body.b, the horns;c, some hairs;d, a solitary horn;e, a large globule;f, some bristles.
K. obovata, versus postica superne sinuata, antice crinita.Plate XXVII.Fig. 21. Egg-shaped, towards the hind-part sinuated, the fore-part hairy.
This animalculum is compressed, and somewhat of a pear-shape; the fore-part broad and blunt; the front is furnished with short hairs or little vibrating points inserted under the edgea, shorter in the hind-parte, partly extended straight, and partly bent down, having a retrograde motion. It is found in water which is covered with lemna.
K. orbiculata, corniculis mediis, antice membranacea ciliata, postice setosa. Orbicular kerona, with the horns in the middle, the fore-part membranaceous and ciliated, and several bristles at the hinder-part.
Differs from the preceding only in having the hinder-part without any bristles.
K. univalvis, antice emarginata corniculata, postice setis flexilibus pendulis.Plate XXVII.Fig. 22 and 23. Kerona with a univalved shell, orbicular, crystalline; the fore-part somewhat notched; the fleshy body lies in the middle of the shell; above and below are hairs or horns of different lengths jutting out beyond the shell, and acting instead of feet and oars, some of which are bent; the superior ones constitute a double transverse row.a, the fore-part;b, the horns;d, a lunated figure in the shell;c, a pulpous body;f, bristles at the hinder-part.
K. ovalis subdepressa, margine altero flexo, opposito ciliato, corniculis anticis, setisque posticis. Oval and rather flat kerona, with one edge bent, the opposite oneciliated, the front furnished with horns, and the hind-part with bristles.
K. ovata, antice sinuata, fronte crestata, basi crinita.Plate XXVII.Fig. 24 and 25. Oval, the fore-part sinuated, a crest on the front, the base hairy.
It agrees in many respects with the trichoda pulex,No. 252; but the upper part is pellucid, without any black molecules; the front truncated, the whole surface of the head covered with hair, and the fore-part sinuous.a, the horns;b, the hairs at the hinder-part;c, the cilia of the front.
K. subclavata, utraque extremitate latiori, hyalina ciliata.Plate XXVII.Fig. 29. Rather clubbed, broad at both extremities, clear and ciliated.
A large animalculum, the fore and hind-part rounded, very pellucid and white, dark in the middle, with black intestines, intermixed with a few pellucid vesicles; both extremities appear as if composed of two thin plates. The fore-part is ciliated, the hairs short, lying within the margin; it is also ornamented with two small horns, erected from an obscure mass; with these it agitates the water, forming a little whirlpool. The hind-part is likewise ciliated, and furnished with two bristles, extending beyond the margin.a, the horns;b, the fore-part ciliated;c, the hind-part;d, projecting bristles.
K. ovata, apice crinito, basi setosa. Egg-shaped, the fore-part hairy, the base furnished with bristles.
The body is egg-shaped, compressed, pellucid, and crowned with short waving hairs, the base terminating with bristles.
K. oblonga, antice et postice crinita, dorso ciliato. Oblong, the fore and hind-part hairy, the back ciliated.
An oval smooth animalculum, somewhat crooked and opake, with a fascicle of vibrating hair on the fore-part; it has a sharp tail, furnished with unequal rows of moveable hairs, producing a rotatory motion; in the inside are some partly lucid, and partly opake points. The figure varies from oval to oblong, the filaments of the conferva are often entangled in the tail.
R. latiuscula, oblonga, antice corniculis micantibus. Rather broad, oblong, with glittering horns on the fore-part.
The body is rather broad and flat, both sides obtuse, filled with black molecules, and there is a dark spot near the hinder-part, where there are likewise a few short bristles. The interjacent vesicles are pellucid; no hairs on the fore-part, but instead thereof two little moveable horns, and from three to five moveable black points. It is found in the infusions of vegetables.
K. ovalis convexa, postice altero margine sinuata, utraque extremitate crinita, corniculisque anticis. Oval, convex, kerona, one edge of the hinder-part sinuated, both ends set with hairs, and some horns placed on the fore-part. This animalculum was found in salt water.
Vermis inconspicuus, pellucidus, cirratus. A pellucid, invisible, cirrated[127]worm.
[127]That is, furnished with a tuft or lock of hair.
[127]That is, furnished with a tuft or lock of hair.
H. ventrosus, postice cirratus, antice acuminatus.Plate XXVII.Fig. 27. Round and prominent himantopus, the hinder-part cirrated, the fore-part sharp.
It is a lively, conical, ventricose animalculum, full of black molecules, the fore-part bright and transparent. The apex, which has long hairs on the under part set like rays, is more or less attenuated, at the will of the little creature; four locks of long and crooked hair, or feet, proceed from the belly; and it is continually moving these and the other hairs in various directions. It is found, though seldom, where the lemna grows.a, the apex;b, the ciliated part;c, the feet.
H. cirrata, supra crinita, cauda sursum extensa.Plate XXVII.Fig. 26. Curled himantopus, the upper part hairy, the tail extended upwards.
This is a lively and diverting animalculum, smooth, pellucid, full of small points, the fore-part clubbed and a little bent, the hind-part narrow; the base obliquely truncated, and terminating in a tail stretched out transversely. The top of the head, and the middle of the backb, are furnished with long vibrating hairs; three moveable and flexible curlsa, are suspended from the side of the head, at a distance from each other. When the animalculum is at rest, its tail is curled; but when in motion, it is drawn tight, and extended upwards, frequently appearing as if it were cleft, as atf.
H. incurvata, supra ciliata, infra crinita. Crooked himantopus, the upper part ciliated, the under part hairy.
This very much resembles the himantopus ludio, the cilia are longer than the hairs, and are continually vibrating; it has twomoveable curls hanging on the side of the head. Is found, though seldom, in water where the lemna grows.
H. lunatus, antice cirratus. Lunated himantopus, the fore-part hairy.
A very lively animalculum, often turning round in a circular direction. Its shape is that of a crescent, with some crystalline points; the convex part is furnished with a row of hairs, which are longest towards the tail, and underneath are four feet.
H. elongatus, medio cirratus. Long himantopus, cirrated in the middle.
The body is rather depressed and long; the hinder-parts acute, and generally curved, pellucid, and filled with granular molecules. Its motion resembles that of the himantopus ludio,No. 275, but its figure, and the situation of its parts are different.
H. cymbæformis fulcata, in fovea ventrali cirrata. Boat-shaped furrowed himantopus, the hollow part of the belly cirrated.
An oval pellucid membrane, the fore-part hairy, furrowed longitudinally, each side bent up, so as to form an intermediate hollow place, or belly, filled with grey molecules; beneath the middle it has several bent diverging rows of hairs; no hairs on the hinder-part. It is found in sea water, but rarely.
H. semiorbiculata, depressa, in utraque pagina cirrata. Semiorbicular himantopus, flattened, both sides cirrated.
A membranaceous lamina, very thin, pellucid, crystalline, and semilunar; the edge of the base is thick set with molecular intestines; the fore-part furnished with short hairs, or a kind of mane; towards the hind-part are three equal curved hairs, or spines.
Vermis contractilis, nudus, ciliis rotatoriis. A naked worm, with rotatory cilia, capable of contracting and extending itself.
V. trapeziformis, nigro-viridis, opaca.Plate XXVII.Fig. 30. This vorticella is in the form of a trapezium, of a blackish green colour, and opake.
It is of an irregular shape, sometimes assuming an oval figure, and appearing as if girt round with a transverse keel,a. It is invisible to the naked eye, ciliated on every side; the hairs all moveable, and longer on one side than the other.
V. cylindrico-globosa, uniformis, opaca. A globous cylinder, uniform and opake.
To the naked eye this appears also little more than a point, but the microscope exhibits it as a globular mass of a dark green colour. It occasions a vehement motion in the surrounding water, which is probably effected by some very short hairs, which are perceptible.
V. cylindracea, uniformis, viridis opaca.Plate XXVII.Fig. 31. Cylindrical, uniform, green, and opake.
This vorticella is visible to the naked eye, appearing like a minute green point; but the microscope discovers it to be nearly cylindrical, of a dark green colour, a little thicker at the fore-parta, than the hinder-partb, and both extremities obtuse. It appears to be totally destitute of limbs; notwithstanding which, it keeps the water in constant motion; so that it has probably some invisible rotatory instrument. It does not change its figure. Its motion is sometimes circular, at others, in a straight line. Atc, some short hairs are visible.
V. viridis, postice lunata, medio margine mucronato. Green vorticella, the hinder part lunated, with a point in the middle projecting from the edge.
The fore-part obtuse, the base broad, and hollowed away like a crescent, with a protuberance in the middle of the concave part shorter than the horns or points of the crescent; the fore-part is ciliated. It is found in salt water.
V. viridis, apertura truncata, papillaque centrali.Plate XXVII.Fig. 32. Green vorticella, the aperture truncated, with a central papillary projection.
Round and prominent, filled with molecules; the fore-part truncated, and both sides of it pellucid; in the center of the aperture there is a prominent papilla or nipple, which when the animalculum is at rest, appears notched; the edge of the aperture is surrounded with cilia; these are sometimes all erect, shining, and in motion, or part bent back and quiescent, and part in motion; sometimes a few of them are collected together, and turned back like little hooks, one on each side. It is found in salt water.a, the cilia;b, the projecting papilla;c, the pellucid space at the fore-part.
V. cylindrica, truncata, opaca, nigricans. Cylindrical, truncated, opake, blackish-coloured vorticella, the fore-part ciliated.
V. ventrosa, apertura orbiculari, ciliis longis raris excentricis. Round and prominent, with an orbicular aperture, and long hairs radiating as from a center.
This is one of the most singular of the microscopic animalcula; when viewed sidewise, it is sometimes nearly cylindrical, but somewhat tapering towards the hinder-part, and having a broad pellucid edge; viewed from the top, it has sometimes a broad face or disc furnished with radiating hairs, the under part contracted into a globular shape, of a dark green colour, and filled with small grains. It was found in October with the lesser lemna.
V. trochiformis nigra.Plate XXVII.Fig. 36 and 37. Top-shaped black vorticella.
This may be seen with the naked eye, appearing like a black point swimming on the surface of the water; the microscope exhibits it as a minute conical body, opake, obtuse, and ventricose at one extremity, and acute at the other. When it extends the extremities, two small white hooks become visible; by the assistance of these it moves in the water, and it is probable from some circumstances that they inclose a rotatory organ. It moves continually in a vacillating manner on the top of the water. It is found in August, in meadows that are covered with water.a, the rotatory organ;b, the two small hooks;c, the acute end.
V. viridis, opaca, varia,vesiculis sparsis. Green, opake, variable vorticella, with vesicles scattered about the body.
The vesicles of this vorticella are larger; in other respects it so much resembles the preceding one, that a further description is unnecessary. It is found in salt water.
V. multiformis, viridis, opaca.Plate XXVII.Fig. 33, 34, 35. Many-shaped vorticella, green, opake.
To the naked eye it appears like a green point, moving with great agility; but, when viewed through a microscope, it assumes such a variety of forms, that they can neither be exhibited to the eye by drawings, nor described by words; it is truly one of the wonders of nature, astonishing the mind, fatiguing the eye, and continually exciting the beholder to ask,
“Quo teneam vultus mutantem protea nodo?”
“Quo teneam vultus mutantem protea nodo?”
“Quo teneam vultus mutantem protea nodo?”
The body is granulous, and a series of pellucid points is sometimes to be observed, as atb b.
Fig. 33, 34, 35, represent this vorticella in three different forms;a, the fore-part;g, the hind-part;c, the fore-part simple;d, the fore-part turned in or doubled.
V. elongata, teres, apertura oblique truncata. This vorticella is long, round, the aperture or mouth obliquely truncated.
This being visible to the naked eye, may likewise be ranked among the larger vorticellæ. The body is somewhat conical,of a dingy red colour; its shape has been compared to that of a grenadier’s cap.
V. Viridis, ventricosa, productilis, antice truncata. Green vorticella, the belly round and prominent, capable of being lengthened or shortened; the fore-part truncated, much in the shape of a common water-bottle; the neck is sometimes very long, at others, very short, and filled with green molecules.
V. subcubica, infra in angulum obtusum producta. This vorticella is somewhat of a cubical figure, the under part bent in an obtuse angle.
It is a very singular animalculum, in shape somewhat resembling the lower part of a boot; the apex of the upper part or leg is truncated and ciliated, the heel pointed, and the foot round. It is to be found in rivers, though very rarely.
V. cubica, infra divaricata. Cubical vorticella, the lower part divaricated.
This is as broad as long, and filled with grey molecules, the apex truncated and ciliated; both angles of the base projecting outwards, one somewhat like a wart, the other like a finger. It is found in marshy waters.
V. ventricosa, antice truncata, papilla caudali et laterali hyalina. Big-belled vorticella, the fore-part truncated, with a papillary tail, and a splendid papillary excrescence on the side. It is found in marshes where the conferva nitida grows.
V. cylindracea, apertura repanda, margine reflexo. Cylindrical vorticella, the aperture broad and flat, the edge turned down.
A thick animalculum, of an equal diameter everywhere, and filled with molecules; the edge of the mouth is bent back, the hinder-part obtuse, sometimes notched and contracted, with cilia on both sides of the mouth.
V. ventrosa, apertura sinuata, cirro utrinque ventrali. Big-bellied vorticella, the aperture sinuated, two tufts of hair on each side of the belly. It is found in ditch water.
V. cylindracea, crateris medio mucrone prominente.Plate XXVII.Fig. 38, 39. Cylindrical, with a prominent point in the middle of the cup.
An animalculum that is invisible to the naked eye; but the microscope discovers it to be furnished with a rotatory organ, which encompasses the middle of the body.
It is pellucid, cylindrical, of an unequal size; the fore-part,a, truncated and ciliated, and a triangular prominence,e, in the middle of the aperture; the hind-part is obtuse, with a point on each side of the middle of the body. This is the appearance of the little creature when in motion; but when the water is nearly exhaled, some further parts of its structure are rendered visible; two rotatory organs are now observable; one on the fore-part, and the other encompassing the middle of the body,h h; the hairs of the latter are in vehement motion. Other fascicles of moving hair may likewise be observed, and the variegated and quick motion of this apparatus is very surprizing, especially if the animalculumbe big with young, moving at the same time within the mother.
V. orbicularis, disco moleculari, peripheria ciliata. Orbicular vorticella, with a molecular disc, and ciliated margin.
V. orbicularis, margine ciliato, subtus convexo-ansata.Plate XXVI.Fig. 8, 9, 10. Orbicular vorticella, the edge ciliated, with a kind of convex handle on the under-side.
V. craterformis, crystallina, medio spærula opaca. Bowl-shaped vorticella, crystalline, with an opake spherule in the middle.
V. cylindrica, postice acuminata. The fore-part cylindrical, the hinder-part tapering, and ending nearly in a point.
V. cylindrica vacua, apice truncata, ciliis prælongis. Empty cylindrical vorticella, the apex truncated.
V. cylindrica, differta, apice truncata, cyliis breviusculis. Cylindrical vorticella, stuffed or filled, the apex truncated, with very short cilia.
This is one of the larger kind of animalcula; the body is crystalline, and replete with black molecules; the skin is perfectly smooth and colourless, the hinder extremity rounded, and the anterior truncated; at this extremity there is a large opening thickly ciliated, which serves as a mouth.
V. cylindrica, truncata, ciliis bigeminis.Plate XXVII.Fig. 60. Cylindrical truncated vorticella, with two pair of cilia.
V. gregaria, cylindracea, oblique truncata, ciliis bigeminis, apice margine fissa. Gregarious cylindrical vorticella, obliquely truncated, with two pair of cilia, and a fissure or notch at the upper edge.
The greater part of the body is cylindrical; the hinder-part rather tapering, and filled with opake molecules; towards the upper end it is transparent; within the edge, at the top are two small tubercles, from each side of which proceed a pair of small hairs.
V. composita, floribus muticis globosis; tentaculis binis, stirpe ramosa,Plate XXII.Fig. 40. Compound, with globous naked florets, two tentacules, and a branched stem. For an ample description of this animalculum, seepage 400.
V. bursæformis, margine aperturæ aculeis rigidis.Plate XXVII.Fig. 40. Purse-formed; the edge of its aperture or mouth set with rigid points.
It is not ciliated, nor have any hairs been discovered upon it; the body is granulated, the fore-part broad and truncated, the hinder-part obtuse, and capable of being contracted or extended.a, the rigid points.
V. subquadrata, ciliorum fasciculis etiam postice.Plate XXVII.Fig. 40, 41. Approachingsomewhat to a square figure, with fascicles of cilia even at the hinder-part.
A lively animalculum, pellucid, round, longer than it is broad, with convex sides; the head is situated at the large end, the skin smooth, and some traces of intestines may be discovered with difficulty. There is a considerable opening surrounded with hair at the larger end, and the filaments composing it are in continual motion. Two of them are sometimes seen joined together, as at Fig. 41, and full of small spherules; in this state they draw each other alternately different ways, the surface is smooth and the hairs invisible.e, moveable cilia.
V. dilatata, pellucida, latere inciso. Dilated, pellucid, with an incision in the side.
To the naked eye it appears as so many white points adhering to the sides of the glass; when magnified, the anterior part is narrower than the hind one; in the side a kind of incision may be perceived, and the hind-part is a little notched towards the middle; it is furnished with a rotatory organ, with which it excites a continual whirling motion in the water.
V. elongata spiculiformis, mox urceolaris. Long spear-formed vorticella, but which often changes its shape into a pitcher-like form.
A pellucid, gelatinous animalculum, of a greenish colour, furnished with small radii, particularly about the circumference, which gives it the appearance of a minute water hedge-hog.
V. folliculo ampulaceo, pellucido, capite bilobo.Plate XXVI.Fig. 4 and 5. This vorticellais contained in a pellucid bottle-shaped bag, the head divided into two lobes.
Little more need be said to enable the reader to know this animalculum, if he should meet with it, than to observe that the bag is nearly in the shape of the common water-bottle, and that the animalculum is sometimes to be observed at the bottom of it, sometimes nearly filling it.
V. oblonga, folliculo cylindraceo hyalino. Oblong vorticella, in a bright cylindrical bag.
This animalculum is gelatinous and cylindrical; when at its greatest extension, the base appears attenuated, and the apex truncated.
V. cylindrica, apertura lunata, spinis caudalibus binis. Cylindrical, the aperture somewhat in the shape of a crescent, two small thorny points projecting from the hinder-part.
The head, the trunk, and the tail, may be easily distinguished from each other. It is of a clay-colour, the aperture ciliated; with a globular projection at times appearing to proceed from it.
V. inverse conica, apertura lunata, trunco postice bidentato, cauda elongata biphylla.Plate XXVII.Fig. 42 and 43. This vorticella is in the shape of an inverted cone, with an aperture the figure of a crescent; the lower part of the trunk is notched, forming as it were two teeth; the tail biphyllous.Each of these parts is surrounded with a loose bright skin, the head is divided from the trunk by a deep incision.a a a, small points projecting from the head;b, the cilia;candd d, the interior parts; Fig. 42,l, the little horn at the bottom of the trunk.
V. cylindrico-ventrosa, apertura mutica, ciliis utrinque rotantibus cauda, articulata biphylla. Cylindrical and big-bellied, the aperture destitute of hairs, both sides of it are furnished with rotatory cilia, the tail biphyllous.
V. inverse conica, apertura lobata spinulosa, cauda brevi unicuspi. Somewhat of a conical shape; the mouth being divided into two parts which are set with small spines, and a point projects from the tail.
It is a pellucid crystalline ventricose animalculum, within the body on one side, there is a large clay-coloured oval mass, and a pellucid oval substance adjacent to it; the tail is articulated and very short.
V. inverse conica, apertura spinosa integra, cauda brevi bicuspi. Somewhat of the shape of a cone, the aperture set with spines, the tail short and divided into two points.
The body is muscular, pellucid, folding variously; the fore-part truncated; round the margin of the aperture are rows of hairs, but it has also stiffer hairs or spines continually vibrating, with which it draws in both animate and inanimate substances. It has some resemblance to the larger vorticella rotatoria, but is easily distinguished from it by its horned spiny aperture, and simple rotatory organ.
V. inverse conica, apertura lobata, setis binis caudalibus.Plate XXVII.Fig. 45. Shaped like an inverted cone, the aperture lobated, the tail small and furnished with two bristles,d.
The body is pellucid, cylindrical, and muscular; the apex about a third part down, drawn into a little neck; in the middle is a little lamina or triangular point; another of these is discovered when the aperture faces the observer, which makes it appear like a small flower. The hind-part, when in motion, is a little bent; it terminates in two minute bristles, which are seen sometimes united, at other times diverging. When the animalculum is swimming, its rotatory organ,a, may be seen; molecular intestines are visible; it moves with velocity in an oblique direction. It is found in pure water.
V. elliptico-ventricosa, apertura integra, cauda annulata biphylla. Elliptical ventricose vorticella, the aperture or mouth undivided, the tail annulated and forked.
There are two kinds of this vorticella; viz. one of a pale yellow, the other of a white colour; the head, the tail, and the trunk, are fully distinguished; a substance in motion has been perceived, which has been supposed to be the heart; they move by fixing their tail to the glass upon the stage of the microscope, and extending their body as much as possible; they then fix the fore-part to the place where they intend to move, and draw the hinder-part to it, proceeding thus alternately. They sometimes turn round about upon one of the points of their tail, at other times they spring forwards with a jerk. When at rest they open their mouths very wide; the lips are ciliated, in some of them two black globules are discovered.
V. subquadrata, apertura integra, spinis caudalibus binis, plerumque unitis. Square vorticella, the aperture not divided, the tail consisting of two long spines, which are sometimes so united as to appear as one.
The body is convex, of a dark colour, and filled with molecules; the middle part is pellucid, the hinder-part rather broader than the fore-part; the latter is ciliated, and the tail formed of two very thin pellucid spines, which are somewhat curved and much longer than the body.
V. elongata, compressa, setis caudalibus binis longissimis. Long vorticella, flat, the tail formed of two very long bristles.
The fore-part sinuated, and set with minute cilia; the two bristles which constitute the tail are long, but one is longer than the other.
V. cylindrica, pedicello collari, cauda longa quadracuspi.Plate XXVI.Fig. 1, 2, 3, 6, 7, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, andPlate XXVII.Fig. 46, 47, 48, and 49. Cylindrical vorticella, with a little foot projecting from the neck, a long tail furnished with four points.
Brachionus corpore conico subæquali. Hill Hist. Anim. Brachionus corpore conico toruloso. Ibid. Brachionus. Pallas Zooph. 50. Joblot Micros, part 2, p. 77, pl. 10, fig. 18; and p. 96, pl. 5, A B C D E K. Adams’s Microgr. Illustr. p. 148, pl. 40, fig. 255. Leeuwenhoeck Contin. Arc. Nat. p. 386, fig. 1, 2. Baker’s Micros. made easy, p. 91-93, pl. 8, fig. 6, 7, 8. Ibid. Empl. for the Micr. p. 267-294, pl. 11, fig. 1 to 13. Spallanz.Opusc. Phys. 2, p. 301, 315, pl. 4, fig. 3, 4, and 5. Rozier Journal Physique, 1775, p. 220.
This animalculum has long been known by the name of the wheel animal; in the description of which no person appears to have succeeded so well as Baker; and to him every writer has since referred for an ample account of this curious little being. What I shall now say on the subject will be chiefly extracted from the same source of information, with such alterations and additions as appear to be necessary to render his account more complete.
I shall begin with observing, that Müller’s wheel animal differs in some respects from that of Baker’s; first, with regard to the rotatory organs which are extended on the back like ears; secondly, the two little splendid substances within the body; and thirdly, the two black points near the top of the head, which are probably the creature’s eyes.
This little animal is found in rain water that has stood for some days in leaden gutters; in the hollows of lead on the tops of houses; or in the slime and sediment left in rain water; they are also sometimes to be met with in ditches and amongst duck-weed.
It has been called the wheel animal, because it is furnished with a pair of instruments, which in figure and motion resemble wheels. It appears only as a living creature when immersed in water; notwithstanding which, it may be kept for many months out of water, and in a state of perfect dryness, without losing the principle of life. When dry, it is of a globular form, about the size of a grain of sand, and without any apparent signs of life.If it be put into water, in the space of half an hour a languid motion begins, the globule turns itself about, lengthens itself by slow degrees, and becomes very lively; in a short time it protrudes its wheels, and swims about in search of food; or else, fixing itself by its tail, brings the food to it by its rotatory organs, which throw the whole circumjacent fluid into a violent commotion; when its hunger is satisfied, it generally becomes quiescent, and sometimes resumes its globular form.
If the water that is found standing in gutters of lead, or the sediment it has left behind, has any appearance of a red or a dark brown colour, little doubt need be entertained of its containing these animalcula. In the summer season, if a small quantity of this dust be put into water, and placed under a microscope, it seldom fails of discovering a great number of minute reddish globules, which are, in fact, the animals themselves. It will be best to view them first with the third or fourth magnifiers, and afterward apply those possessing greater powers.
The motions of this little creature somewhat resemble those of a caterpillar; like many of those insects, removing itself from place to place by first fixing the tail to some substance, then extending the whole body, fixing the head, and afterward drawing the tail to it; by these alternate actions it moves with some degree of swiftness.
This animal frequently changes its appearance, and assumes a very different form; for, the snout being drawn inwards, the fore-part becomes clubbed, and immediately dividing, exhibits to our view two circular instruments set with minute hairs, that move very briskly, sometimes in a rotatory, at other times in a kind of trembling or vibratory manner. An aperture or mouth isalso perceived between the two semicircles; whilst in this state, the animal may often be perceived swimming about in pursuit of food.
The most distinguishing parts of this animalculum are, the head, the thorax, and the abdomen. It differs from any other creature hitherto described in the wonderful form and structure of its head; the sudden changes of which from one form to another are equally surprizing and singular; from being of a very taper form, it becomes almost instantaneously as broad as any part of its body, and protrudes an amazingly curious machinery formed to procure its food.
The circular bodies which project from the animal have much the resemblance of wheels, appearing to turn round with considerable velocity, by which means a very rapid current of water is brought from a great distance to its mouth. As these wheels are very transparent, the edges excepted, which are set with fibrillæ, as cogs to a wheel, it is difficult to determine how the rotatory motions are performed, or whether their figure be flat, concave, or conical; be this as it may, they are protruded from a couple of tubular cases, into which they can be again withdrawn, at the will and pleasure of the animal. They do not always turn the same way, nor with the same degree of velocity, sometimes moving in opposite directions, at other times both one way. The figure varies according to the degree of their protrusion, as well as from other circumstances. They appear occasionally like minute oblong squares, rising from the periphery of a circle; at other times they terminate in sharp points, and sometimes they are curved, bending the same way like so many hooks; now and then the ends appear clubbed, or in resemblance like a number of small mallets.
When the fore-part of this creature is first seen to open or divide, the parts, which when fully protruded resemble wheels, seem only like a couple of semicircles, the edges of which are set with little spiculæ, having a nimble, and continually vibrating motion upwards and downwards, for the purpose of agitating the water, each wheel being in this case doubled, or like a round piece of paper folded in the middle.
When the wheels are in motion, the head appears very large in proportion to the size of the animal; and though it is then everywhere transparent, yet a ring or circle, more particularly distinguished by its brightness, may be perceived about the middle of the forehead, from whence many vessels are seen to originate.
The thorax or breast is united to the head by a short annular circle or neck; the size of the thorax is nearly one-sixth part of the whole animalculum. In it the heart is distinctly seen; being placed nearly in the center, the diastole and systole cannot fail to attract the eye of every attentive observer; the alternate dilatation and contraction is very perceptible through the back of the animal, being performed with great strength and vigour. It appears to be composed of two semilunar parts, which in the time of contraction approach each other laterally, and form between them a figure somewhat like a horse-shoe, whose upper side is flat, the under one convex. In the diastole, these two parts separate; the separation begins exactly in the middle of the lower part next the tail. In each of the semilunar parts there is a cavity, which closes when they come together; and opens when they separate.
The motion of the heart is communicated to all the other parts of the thorax, and indeed through the whole animal. It is necessaryhowever to remark, that this motion is sometimes suspended, or at least quite imperceptible, for two or three minutes, after which it re-commences, and goes on with the same vigour and regularity as before. From the under part of the thorax a small transparent horn proceeds, which cannot be seen unless the insect turns on its back or side.
Below the thorax there is an annular circle that joins the thorax to the abdomen; this is considerably the largest part of the animal, and contains the stomach and viscera. When full of food, the intestines are opake, and of a crimson colour, extending from the thorax quite through the abdomen and a great part of the tail, exhibiting a fine view of the peristaltic motion, or those gradual contractions and dilatations of the intestines, which propel their contents downwards. Numerous ramifications of vessels, both longitudinal and transverse, surround the intestines. The abdomen is not only capable of contraction, but also admits of such a degree of extension, as to form a case for all the other parts of the body. The tail extends from a joint at the lower part of the belly to the posterior extremity; it is of a tapering form, and consists generally of three joints; when the animal is inclined to fix itself to any thing by the tail, it thrusts out four, sometimes six, little hooks from the extreme part; these are placed in pairs, one at the very extremity itself, the other two a little way up the sides; the three pair are seldom seen at the same time. The wheels appear to be the organs used by the animal to assist it in swimming.
All the actions of this creature seem to imply sagacity and quickness of sensation; at the least touch or motion in the water, they instantly draw in their wheels. Baker conjectures that they have eyes lodged near the wheels, because while they are in the globular or maggot state, their motions are slow and stumbling;but after the wheels are protruded, they are performed with great regularity, swiftness, and steadiness. Can we sufficiently admire the wonderful contrivance in the apparatus of this animal? a being so diminutive, as not to exceed in size a grain of sand!
Plate XXVI.Fig. 17, represents the wheel animal in what Baker calls the maggot state; while in this form small spiculæ are seen to dart out near the anterior part; the snout is sometimes more, at other times less acute than in this delineation.a, a small horn near the thorax.
Fig. 15 represents its manner of moving from place to place, while in the maggot state.a, the projecting horn.
Fig. 12 exhibits it with the two semicircular parts,a a, protruded, and in the posture in which it places itself, when preparing to swim about, or going to set its wheels in motion.
Fig. 1 shews the head at its full extent, and a couple of small bodies,a a, on the top of it, armed with small teeth,b, like those of the balance-wheel of a watch.
At Fig. 18 the interior parts are more particularly exhibited.a, the circle from which many vessels originate;b, the thorax or breast, joined to the head by the neck,c; the part which is supposed to be the heart is plainly seen atd; the abdomen,f, is separated from the breast by a ring,e;g, the tail.
Fig. 19 exhibits the animal not fully extended, though with its wheels in motion.
Fig. 20 shews it with its side towards the eye; in this position one of the wheels,a, appears to lie considerably below the other.
Fig. 6 and 16 represent two of these creatures in the postures in which they are frequently seen when the wheels are not protruded, but with the fibrillæ,a b, vibrating quickly.
Fig. 2 exhibits the animal with the body nearly drawn into the abdomen; at Fig. 21, the body still further drawn in; at Fig. 22, as it appears with the tail partly drawn in; at Fig. 23, in a globular form, but still adhering by the tail.
Sometimes, when in the maggot form, it rolls its head and tail together, without drawing them into the body; as represented at Fig. 14.
Baker has also described three other species, one of which, differing only from the preceding in having a very long tail, is represented at Fig. 7.
Fig. 11 is another kind, with crustaceous spiculæ,b, at the fore-part; within this, atc, an opake oval body may be seen, which has been taken for an egg.
Fig. 3 is another kind; it has two projecting points,a a, from the tail, and the head furnished with a number of fibrillæ,b b.
Fig. 13 represents another species, described by Spallanzani.
Plate XXVII.Fig. 46, 47, 48, 49, represent the wheel animals seen and delineated by Müller.a, the head;b, the eyes;c, a small horn;d, the rotatory organ;e, the tail;f, the points of the tail.
V. cylindrica, apertura integra, cauda longiuscula bifida. Cylindrical vorticella, the aperture undivided, the tail rather long, and divided into two parts.
A cylindric body with a rotatory organ, consisting of a row of hairs at the apex; the tail is divided into two parts turning a little inwards. When at rest, it joins the segments of the tail; but opens them when in motion. It is generally found in common water.
V. cylindracea, apertura mutica, cauda perbrevi, reflexa, bicuspi.Plate XXVII.Fig. 50. Cylindrical vorticella, the aperture plain, the tail short, bent back, and divided into two points.
It is a little thick muscular animalculum, folding itself up; of an equal breadth throughout, the body disfigured by longitudinal folds winding in various directions; the anterior part or head is connected to the body by a little neck, and it occasionally exhibits a very minute rotatory organ. The tail,e, is short, terminating in two very small bristles,d, which are exposed or concealed at pleasure; the intestines ill-defined. Its motion is rotatory, but in different directions. It is commonly found in marshy waters.
V. cylindracea, apertura mutica, cauda brevi, articulata, bicuspi. Cylindrical vorticella, the aperture plain, with a short articulated tail divided into two pointed parts.
V. caudata, cylindracea, mutica, cauda spinis duabus longis terminata. With a tail, cylindrical, beardless, the tail terminating in two long spines.
The body is large, the apex of an equal thickness, obtuse, with rotatory filaments; the tail acute, with two pellucid spines, in length about one-third part of the body, alternately separating from and approaching each other.
V. caudata, elongata, tubæformis limbo ciliato. Long-tailed vorticella, trumpet-shaped, the arms furnished with rows of short hairs. See this fully described by the name of hydra stentorea, inpage 392.
V. caudata, aggregata, clavata; disco obliquo. A description of this vorticella has also been given, as hydra socialis, inpage 395.
V. caudata, aggregata, oblongo-ovata, disco dilatato pellucido.Plate XXVII.Fig. 51 and 52. With a tail aggregated, of an oblong oval shape, with a dilated pellucid disc.
To the naked eye it appears as a yellow globule, adhering to the ceratophyllum, or common horn-wort, Fig. 52,a, like a little flower; or a heap of yellow eggs,b. With the assistance of the microscope they are discovered to be a congeries of vorticellæ, constituting a sphere from a mouldy center. They contract or extend their bodies either when alone or associated, and excite a vortex in the water by means of the disc. When they quit the society, and act singly, their parts may be more readily distinguished, and will be found to consist of a head, abdomen, and tail. The head is often drawn back so far into the abdomen, that it cannot be seen, exhibiting only a projecting, broad kidney-shaped disc. The abdomen, Fig. 51,d, is oblong, oval, and pellucid, replete with obscure intestines, amongst which are one or two remarkable blackoval spots,e; the tail,f, is sharp, twice as long as the abdomen, either rough and annulated, or altogether smooth.
V. simplex, multiformis, orificio contractili, pedunculo æquali.Plate XXVII.Fig. 53. Simple, many-shaped, with an orifice admitting of contraction, and equal-sized foot-stalk.
The head is full of molecules, round, everywhere of an equal size, and very pellucid; both sides of the orifice are ciliated, and each has a rotatory motion, appearing sometimes without the edge of the mouth, as ata a; at other times within it. No distinct intestines or internal motion are perceivable. Its motion is different from most of this genus, but not easily described; atc care small feet. It is found in stagnant water.
V. simplex, obovata, pedicello minimo retractili. Simple, somewhat oval, with a very small retractile foot, which it can draw within itself.
V. simplex, turbinata, apice bituberculata.
Simple vorticella, the upper part broad, the under part small, with two projections at the anterior end, furnished with a number of fibrillæ, which produce a current of water by their vibration, and thus collect food for the animal. Baker has delineated it in Plate XIII. No. 10, 11, 12, of his Employment for the Microscope.
V. simplex, obovata, pedunculo minimo, orificio contractili. Simple, somewhat of an ovalshape, with a small pedicle, and an orifice which it contracts or dilates.
The small head, or rather body of this little creature is pear-shaped, pellucid, the middle of the aperture convex, both sides ciliated, the pedicle four times shorter than the body; it can contract the orifice to an obtuse point.
V. simplex, deflexa, pedunculo brevi, capitulo retractili. Simple, bent, with a short pedicle, and small retractile head.
This has a pellucid pendulous little head; the anterior part truncated, occasionally contracting itself twice as short as the pedicle; its shape resembles that of a tobacco-pipe.
V. simplex, erecta, ovato-truncata, pedunculo vaginato. Simple vorticella, erect, of the shape of a truncated egg; the pedicle is contained in a sheath.
For the 337th, 338th, and 339th, the author refers to the Zool. Dan. he terms them, vorticella cyathina, vorticella putrina, vorticella patellina.
V. simplex, sphærica, pedunculo retortili. Simple, spherical, with a twisted pedicle.
This animalculum has a small spherical head, the aperture of the mouth ciliated; the pedicle four times longer than the body, which it contracts into a spiral form. It is frequent among the cyclopa quadricorni.
V. simplex, hemisphærica, pedunculo retortili.Plate XXVII.Fig. 54. Simple, hemispherical, with a twisted pedicle.
The small head of this animalculum is goblet-shaped, the margin of the orifice protuberant, ciliated on both sides, with undulating hairs; the pedicle eight or ten times the length of the body. The pedicle extends itself as often as the mouth is opened, but is twisted up spirally when it is shut; and these motions are frequently repeated in a short space of time,a a, the head when expanded;b, when shut;c, the undulated edge;d d, the cilia erect;e, when horizontal;f, the pedicle when straight;g, when bent in a spiral form.
V. simplex, campanulata, pedunculo retortili. This animalculum, the bell-animal of Baker, has been fully described inpage 407.
V. simplex, turbinata, pedunculo retortili. Simple, with a twisted turbinated pedicle.
The pedicle is simple, and twists itself spirally; is extremely slender, with a kind of cap on its head; the margin white and round, and appearing as if encompassed with a lucid ring; the head diminishes towards the base. It is transparent.
V. simplex, ovata, pedunculo reflexili.Plate XXVII.Fig. 66. Simple, egg-shaped, the pedicle bent back.
The body is narrow at the base, open and truncated at the top; the margin apparently surrounded with a ring; but, when the aperture is shut, the animalculum is egg-shaped, with a simplesetaceous pedicle, considerably longer than the body, and generally much bent back.a a a, the head open;b, partly closed;c, quite shut;d, the stalk when straight; and ate, when bent.
V. simplex, truncata, pedunculo apice retortili. Simple, truncated, with a pedicle twisted at the end.
This is visible to the naked eye; when contracted, it appears to be annulated; the head is an inverted cone, convex when the mouth is shut, but truncated when it is open, and with a protuberant edge; the pedicle is simple, very long and thick, whiter at the top than any other part, and formed into a little head; the apex is twisted spirally.
An ample description of this animalculum, under the title of vorticella umbellaria, has been given inpage 402.
V. simplex, viridis, campanulata, margine reflexo, pedunculo retortili. Simple, green, bell-shaped, the margin or edge turned back, the pedicle twisted.
The head is bell-shaped, green, opake, narrow at bottom, pellucid. It has a rotatory organ, which may sometimes be seen projecting beyond the aperture; there is a little head at the apex, and the pedicle is twisted and very slender. A congealed green mass, which is often swimming about in ditches, is composed of myriads of these animalcula, which are invisible to the eye, but when magnified, appear like a bundle of green flowers.
V. simplex, citriformis, pedunculo retortili. This may be classed among the most minute. Thehead resembles a citron, the apex is truncated, the base narrow; a gaping cleft is observable descending from the apex, to one-third of the body.
V. simplex, hemispherica, margine contractili. Simple, hemispherical, with a margin which it can contract at pleasure.
The body is of a yellow colour, much resembling the flower of a daisy; the head scarcely pellucid; the internal part quite filled; it is abundantly ciliated round the margin, moving in a rotatory manner.
The foot or pedicle is long, slender, and pellucid; it is divided into two parts, with small knobs on the top of each; the base adheres to a bulb, the under-part is covered with small scales.
V. simplex, sphærica, capitulo gemino. Simple, spherical, with a double head.
The pedicle is long, and constantly furnished with two small heads at its apex; these are bright and clear.
The distinguishing characters of this animalculum will be found atpage 400.
A full description of this vorticella has also been given atpage 397.
Atpage 406the reader will likewise meet with an account of the v. digitalis.