THE PHYSICAL BASIS OF MENDELISM 409 
and the other from the male with the chromosomes in full black, unite 
to form the female zygote shown in the middle of the figure. The 
combinations of maternal and paternal chromosomes which result in 
the production of germ cells in such an individual are shown diagram- 
KK Dit 
SO |\ 
— 
, a’ 
e 
. => 
———~ 
wd 
° 
WA A 
Fic. 74.—Diagram showing consequences of independent segregation of 
chromosomes in Drosophila ampelophila. (From Babcock and Clausen.) 
matically in the lower portion of the figure. There are eight different 
ways in which the chromosomes may be grouped in the reduction 
figures and on the basis of chance any one of these types is.as likely 
to occur as any other. As a result there are sixteen possible combi- 
nations of chromosomes in the germ cells with respect to the original 
