26 



THE HUMAN BODY 



reference to the various species of living beings is to maintain them 

 upon earth from generation to generation. The life of the individ- 

 ual is important only as it serves toward the perpetuation of the 



7 : 



Y 



/ \ 



FIG. 7. Diagram showing the changes which occur in the centrosomes and 

 nucleus of a cell in the process of mitotic division. (Schafer.) The nucleus is sup- 

 posed to have four chromosomes. 



