7 82 



DEVELOPMENT 



spermatids from each secondary spermatocyte. Each spermatid receives 

 half the chromosomes of each diad, and as a result a spermatid possesses but 



Spermatozoa 



FlG. 499. 



a single set of simple chromosomes. It is then said to have the reduced or 

 gametic number, characteristic of sexual germ ceils, as contrasted with the 



FIG. 500. 



FIGS. 499 and 500. Diagrams Showing the Scheme of Development and Chromatin 

 Reduction in the Growth of the Spermatozoa and Ova. (From Cunningham.) 



unreduced or somatic number, characteristic of the cells of the body. 



The spermatid is metamorphosed directly into a spermatozoon. The 



