1 8 J. E. WODSEDALEK. 



four plus the two accessories in the other type. Not only is the 

 bivalent nature of these large autosomes conspicuous, but very 

 frequently a quadrivalent character is discernible and they are 

 much larger than the accessories (Figs. 44, 45, 46 arid 47). 

 During the anaphase the bivalent nature of the chromosomes is 

 often clearly visible at each pole. Figure 49 shows four bivalents 

 and is a drawing of one pole of the dividing cell which received 

 eight chromosomes during the first maturation division. Figure 

 52 is a drawing of one pole of the division of the type of secondary 

 spermatocyte which received eight ordinary chromosomes and 

 the double accessory. It will be seen that four of these are bi- 

 valent in nature, while two are univalent, the two univalents 

 being the results of the division of the two accessories (Figs. 44, 

 50 and 51) both of which have here divided for the first time 

 since the spermatogonial division. The bivalent nature of the 

 autosomes after the second spermatocytic division becomes even 

 more conspicuous in cases where these chromosomes divide into 

 two before they break up. Figure 56 shows an early spermatid 

 cell which received the four bivalent autosomes and the two 

 accessories. It can be seen that two of the autosomes have 

 almost completely divided. The bivalent nature of the other 

 two can also be plainly seen, wiiile the accessories retain their 

 univalent appearance. Thus it can be seen that the spermatids 

 produced by this second division do not receive four and six 

 chromosomes respectively, but, four bivalents, or the equivalent 

 of eight univalents, are present in the one type of cell, and four 

 bivalents or eight univalents together with the two accessories 

 in the other. The foregoing facts seem to indicate beyond doubt 

 that the second maturation division is not a reduction but simply 

 an equational one. 



Figures 50 and 54 represent an anaphase of division in a 

 secondary spermatocyte showing two streaks of lagging chro- 

 matic material. Although several such cases were observed 

 ordinarily no such pronounced streaks occur (Fig. 51). Guyer 

 found a similar condition in the secondary spermatocyte division 

 in man and suggests that it may be the two accessories lagging 

 behind. Although many accurate counts of the chromosomes in 

 this second division were made, they were so massed together 



