126 THEORY OF EVOLUTION 



In man the sex formula appears to be XX 

 for the female and XO for the male ( fig. 60 ) , 

 and sinee the relation is essentially the same as 

 that in Drosophila the chromosome explanation 



^f'f </etcrmiJi<rticn in niaii ( lli/iiiiinlcr ) 









KiG. 01. Spermatogenesis in man. Tliere are 47 ehromo- 

 somes ((li])l()id) in the male. After veduetion half of the 

 .sperm earry 2i ehromosomes (one of whieh is X) and half 

 cari'v 315 eliromosomes (no X). 



is the same. According to von Winiwarter 

 there are 48 chromosomes in the female and 47 

 in the male (fig. (51). After the extrusion of 

 the polar bodies there are 24 chromosomes in the 

 itgl^. In the male at one of the two matiu'ation 



