74 DESCRIPTION OF PLATES. 



Platb XV. 



A^hro^hora quadrangularis. 



Figs. 264-265. Second spermatocyte, telophase, showing chromatin nucleolus («) 

 and the products of division of the odd chromosome (x). 

 266. A spermatid containing the chromatin nucleolus (re). 

 267-268. Spermatids containing both the chromatin nucleolus (») and the odd 

 chromosome (x), a the acrosome. 



269. Equatorial plate from a somatic cell of a male larva, 23 chromosomes. 



270. Equatorial plate of an oogonium, 24 chromosomes. 



271. Resting nucleus of a young oocyte before synapsis, showing two pairs 



of condensed chromosomes, corresponding in size to the Tre-chromo- 



somes and the odd chromosome of the spermatocytes. 

 272-277. Sections of nuclei of oocytes, showing one or more of these hetero- 



chromosomes, from safranin-gentian preparations. 

 278-279. Bouquet stage from iron-haematoxylin preparations, showing the 



heterochromosome bivalent (a;). 



Caccecia cerasivorana (Lepidoptera) . 



280. First spermatocyte, synizesis stage, showing 2 condensed chromo- 

 somes {xi and xjs). 

 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. 



Euvanessa antio^a (Lefiidoftera). 



293. First spermatocyte, equatorial plate. 



