Fig.237. Resting primary spermatogonium with lobed nucleus.
238. Resting secondary spermatogonium, with nucleus staining much more deeply.
239. Equatorial plate of secondary spermatogonium, 23 chromosomes.
240. First spermatocytes, very early growth stage,xthe odd chromosome.
241-243. First spermatocyte, later spireme stages, showing the odd chromosome (x) and a pair ofm-chromosomes (m).
244. Similar stage from a safranin-gentian preparation.
245. First spermatocyte, split-spireme stage,xthe odd chromosome,mthem-chromosome tetrad.
246. Similar stage from a safranin-gentian preparation.
247-248. First spermatocyte, condensation of chromatin granules to form tetrads in the linin spireme.
249. Later tetrad stage.
250-251. First spermatocytes, metaphase from mercuro-nitric material.
252-254. Similar stages from Hermann material, showing longitudinal split in both the bivalents, and the odd chromosome (x).
255. First spermatocyte, anaphase.
256. First spermatocyte, telophase.
257. First spermatocyte, daughter plates containing 11 and 12 chromosomes, respectively.
258. First spermatocyte,aandcdaughter plates, each containing 11 chromosomes,xthe odd chromosome at a different level (b).
259. Second spermatocyte, equatorial plates of the two classes.
260. Second spermatocyte, metaphase.
261. Second spermatocyte, anaphase.
262-263. Second spermatocyte, daughter plates of the two classes.
Figs.264-265. Second spermatocyte, telophase, showing chromatin nucleolus (n) and the products of division of the odd chromosome (x).
266. A spermatid containing the chromatin nucleolus (n).
267-268. Spermatids containing both the chromatin nucleolus (n) and the odd chromosome (x),athe acrosome.
269. Equatorial plate from a somatic cell of a male larva, 23 chromosomes.
270. Equatorial plate of an oögonium, 24 chromosomes.
271. Resting nucleus of a young oöcyte before synapsis, showing two pairs of condensed chromosomes, corresponding in size to them-chromosomes and the odd chromosome of the spermatocytes.
272-277. Sections of nuclei of oöcytes, showing one or more of these heterochromosomes, from safranin-gentian preparations.
278-279. Bouquet stage from iron-hæmatoxylin preparations, showing the heterochromosome bivalent (x).
280. First spermatocyte, synizesis stage, showing 2 condensed chromosomes (x1andx2).
281-282. First spermatocyte, synapsis stage.
283-284. First spermatocyte, growth stages.
285. First spermatocyte, prophase.
286-287. First spermatocyte, later prophases, showing the heterochromosome pair (x).
288. First spermatocyte, metaphase.
289. Second spermatocyte, metaphase.
290. First spermatocyte, equatorial plate.
291-292. Second spermatocyte, equatorial plates.
293. First spermatocyte, equatorial plate.