430 Evolution and Adaptation 
equal parts, so that we find now three polar bodies and the 
egg (Fig. 6 G). A strictly analogous process takes place 
in the formation of the spermatozoa (Fig. 7 B-F). The 
mother-cell of the spermatozoon divides into two parts, which 
are equal in this case (Fig. 7 B-D). Each of these then 
Fic. 6.— Diagram showing the maturation of the egg. 
divides again (Fig. 7 E, F), producing four cells that are 
comparable to the three polar bodies and the mature egg. 
Each of the four becomes a functional spermatozoon (Fig. 
7G,H). Thus while in the maturation of the egg only the 
egg itself is capable of development, in the case of the male 
cells all four products of the two maturation divisions are 
functional. 
