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THE PERPETUATION OF ADAPTATIONS 



JB* 



//I 



FIG. 91. Diagram showing the distribution of the chromosomes in the two 

 maturation divisions of the male (cf) and female (9) germ cells of the nematode 

 worm Ascaris. The light spot at the end of some of the chromosomes may 

 represent a group of characteristics (e.g., sexual characters), and its distribution 

 to spermatozoa and mature eggs is shown in the history of the two divisions. 

 (From Morgan.) 



