266 



GERM-CELL CYCLE IN ANIMALS 



1910). The eggs laid by the stem-mother (see Chap- 

 ter I, p. 24) in the spring possess four ordinary and 



C 



FIG. 71. Stages in the spermatogenesis and oogenesis of the honeybee. 

 A, B. First maturation division in the male. C. Second matura- 

 tion division in the male. Three cells are produced : the first (RK{) 

 without chromatin ; the second (RK%) with chromatin, but small 

 and functionless ; and the third a functional spermatid. (After 

 Meves, 1907.) 



D. First maturation division in the female showing polar body 

 with eight dyads, and secondary oocyte with eight dyads. E. Sec- 

 ond maturation division in the female showing the divided first 

 polar body, the second polar body, and female pronucleus each with 

 eight monads. F. Outer end of first polar body disintegrating ; 

 inner half of first polar body uniting with second polar body, and 

 female pronucleus. (After Nachsheim, 1913.) 



two sex chromosomes. These eggs give rise to 

 parthenogenetic females with the same number of 



