No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 23 



the body, which I will directly describe as the chromoplast. It 

 is quite possible that both these processes have taken place, as 

 the chromoplasm found in the chromoplast is not sufficient to 

 account for the quantity found in the chromosomes at a later 

 stage. That the chromoplast has something to do with the 

 formation of the chromoplasm is more than probable, because 

 at the time when the spireme segments are being formed, the 

 chromoplasm is seen to be thicker nearer the chromoplast, 

 while at the distal end from the chromoplast the chromoplasm 

 is thin or very thin. It sometimes seems as if the chromo- 

 plasm had flowed from the chromoplast and been gradually 

 distributed all along the spireme segment. It seems also prob- 

 able that the chromoplasm is a prominent constituent in the 

 chromoplast — at least the only visible differentiation between 

 the chromoplasm in the spireme and the chromoplasm in the 

 chromoplast is that the former stains less intensely than the 

 latter. In most papers on cytology the chromosomes are 

 figured with their margins drawn out into the linin network. 

 I think this is probably an error caused by imperfect staining, 

 as in all my best preparations I could distinctly see that the 

 chromoplasm always possessed a rounded margin, and that the 

 points consisted exclusively of linin which at times may be so 

 stained that it cannot be distinguished from the chromoplasm. 

 TJie Chro7nomeres. — But little need be said about the chro- 

 momeres, as they will be again referred to in describing the evo- 

 lution of the nucleus. The chromomeres begin to form as soon 

 as the nucleus of the polymorphous cells enters the imperfect 

 resting stage. The chromomeres are formed in the follow- 

 ing manner : Two, and later three, chromioles which, during 

 the perfect resting stage, were suspended singly in the linin, 

 come together and are at the same time seen to be surrounded 

 by a thin layer of chromoplasm, thus forming a small isolated 

 body suspended in a linin network. The chromoplasm soon 

 increases in quantity, and the chromomere is in this way in- 

 creased in size. The number of chromioles present in each 

 chromomere is not always the same in the early prophases, and 

 some chromomeres may possess twice the number of chromi- 

 oles as some others. Still the number is fairly constant, gen- 



