166 



R. VENDRELY 



TABLE VI 



DNA Content (Picograms per Nucleus) of Somatic Cells of Various 



Vertebrates 



Numbers in parentheses indicate references. 



whose karyotypes are not analy sable by the method of comparative cyto- 

 logy." This author has studied the relative amounts of DNA per spermatid 

 nucleus in eight species of Mantidae by photometric measurements and 

 compared this amount with the number of chromosomes and their size (total 

 length in arbitrary units). In one case this comparison suggested the pos- 

 sibility of polyploidy in the evolutionary process; in other cases, the DNA 

 content was the same in two species in which the number of chromosomes 

 was very different and in which polyploidy was evident. Moses and Yer- 



