SEGREGATION OF HOMOLOGOUS CHROMOSOMES 471 



to be the case in figure 62a (plate 11). Information derived 

 from the same source would lead us to expect seventeen atelo- 

 mitic chromosomes in individual number 22. Such a meta- 

 phase is shown on plate 11, figure 22a. Figures 62a and 626 

 are spermatogonial metaphases from the same animal and have 

 seven atelomitic chromosomes, as we would expect from the 

 first spermatocyte complex of this individual (plate 9, 62). 



Figures 70a and 75 (plate 11) are spermatogonial complexes 

 from Circotettix lobatus. The significant difference from simi- 

 lar complexes of Trimerotropis is that they have twenty-one 

 instead of twenty-three chromosomes. In regard to the atelo- 

 mitic members the conditions are the same as in Trimerotropis, 

 that is, the number of such dyads is the same in both sperma- 

 togonial and first spermatocyte metaphases. The number is 

 twelve in these two cases. Figure 70a is from the individual 

 in which tetrad number 1 divides very unequally in the first 

 spermatocyte. It will be seen from this figure that the smallest 

 two homologues are equal in size but one has median a fiber 

 attachment. This agrees with the expectations from the study 

 of the prophases of the first spermatocyte which showed a nor- 

 mal tetrad. We have then in the tetrad which divides un- 

 equally in the first spermatocyte, in reality a J-shaped tetrad 

 which is dividing at the point of fiber attachment in the atelo- 

 mitic dyad. 



c. Female somatic complexes. Unfortunately, the maturation 

 stages in the female are inaccessible because they do not 

 take place until a few hours before or even after the egg is de- 

 posited (Henking '91), and the great quantity of yolk present 

 has so far defied all efforts at sectioning. Immature ovaries 

 are readily sectioned and contain numerous divisions in the 

 follicular cells. The^e have been used for the somatic com- 

 plexes. Morrill ('10) found from a study of the cleavage and 

 early blastoderm stages of some Coreid Hemiptera that the 

 number and size relations of the chromosomes in the somatic 

 cells of the males and females are the same as in the sperma- 

 togonia and oogonia, respectively. Three females were studied 

 by me, the complex proving constant for the individual, but 



