THE PHYSICAL BASIS OF MENDELISM 4II 
the male the three pairs of autosomes which are exactly like those in the 
female are outlined, but the X-chromosome and the Y-chromosome are 
drawn in black. The reduction division in the female results in a 
} 
| | REDUCTION | 
DIVISIONS 
+0 
Q 
Fic. 75—Diagram to show chromosome relations in the inheritance of sex 
in Drosophila ampelophila. (From Babcock and Clausen.) 
separation of the members of each pair of chromosomes, so that every 
secondary germ cell (or egg) contains two large curved autosomes, 
a small autosome, and an X-chromosome. Consequently as far as 
chromosome content goes the eggs are all exactly alike. In the male, 
