IIO CHARLES V. MORRILL. 



the history of the chromatin in the early stages. Considered 

 from this standpoint, the results briefly are as follows: 



Dipt era. Apart from the earlier works of \Yeismann and 

 Blochmann in which the chromosomes were not especially con- 

 sidered, there are no observations except those of Henking ('88 

 and '93) on Musca vomitoria. In the first paper Henking figured 

 the cleavage spindles but did not determine the number of chro- 

 mosomes. Moreover, the results are difficult to interpret because 

 of the standpoint taken in regard to "free-nuclei-formation." 

 In the later paper Henking summarizes his previous results but 

 gives no new observations. 



Lepidoptera. Platner ('88) described briefly the maturation 

 and early cleavage of the parthenogenetic and fertilized eggs of 

 Liparis dispar but gave no figures and no account of the chromo- 

 somes. . Henking ('90) described and figured the maturation, 

 fertilization and early cleavage of Pieris brassiccz. He found 

 the haploid number of chromosomes to be 14 in both polar 

 spindles and in the female pronucleus, but did not accurately 

 determine the diploid number, though in a later paper he gives 

 the probable number as 28. The same author ('92) gave a brief 

 account of the maturation and early cleavage of Bombyx mori 

 and Leucoma salicis in which the haploid chromosome-group was 

 stated to be "at least 12," in both species. The diploid number 

 was not determined. 



Neuroptera. As far as I am aware, there are no observations 

 on the maturation and cleavage of mitoses of the eggs of this 

 group. Miss McGill's ('06) observations on An ax junius and 

 Plathemis lydia were confined to the nuclear changes during the 

 growth period of the oocytes. 



Coleoptera. Wheeler ('89) observed the formation of the first 

 polar spindle of Leptinotarsa (Doryphora) decemlineata but did 

 not determine the number of chromosomes. Henking ('92) in 

 Agelastica alni found the haploid number of chromosomes to be 

 about 12 in both polar spindles and the diploid number, 24-30 in 

 the cleavage spindles. He also observed the approximate num- 

 ber in Lampyris splendidiila, Adlmonia tanaccti, and Doinuin 

 (sericea L.?). In none of these, however, did he observe the 

 diploid groups in the cleavage stages. The- nb-i-rvutions of 



