198 



BARBARA HEFFNER. 



one-cell stages examined with reference to this point, I found in 16 

 cases two, and in 18 three such chromosomes. Fig. I, a, illus- 

 trates a case with two V-shaped chromosomes in each daughter 

 plate. Their antagonistic position proves that they are division 



Ib 



^ 



2c 



2a 



2b 



3a 



3b 



r 



FIGS. 1-5. 



products of the same chromosome, their regular number, that 

 they are not merely incidental features. The other chromo- 

 somes are very crowded, as most of them occur in one section. 

 Their position has been slightly changed in cases where they were 



