CHROMOSOMES AND MITOCHONDRIA 273 



TABLE SHOWING THE NUMBER OF CHROMOSOMES IN MAN 

 ACCORDING TO VARIOUS INVESTIGATORS 



which became ten bivalent and two accessories in 

 the primary spermatocytes. The latter pass un- 

 divided to one pole (Fig. 75, -4), and hence two classes 

 of spermatozoa result, one with ten ordinary chromo- 

 somes, and the other with ten ordinary and two 

 accessory chromosomes. Winiwarter (1912), on the 

 other hand (Fig. 75, D-E), reports forty-seven 

 chromosomes in the spermatogonia and two classes 

 of spermatozoa, one with twenty-three and the 

 other with twenty-four. The number in the female, 

 according to Winiwarter, is probably forty-eight, 

 and hence all mature eggs are alike so far as chromo- 

 some number is concerned, each being provided 

 with twenty -four. If these data are confirmed, it is 

 evident that sex in man is determined at the time 

 of fertilization and cannot be influenced by changing 

 the environment. 



1 Wilcox doesn't state whether this is the reduced or diploid number. 

 T 



