158 R. VENDRELY 



TABLE I 



Amount of DNA per Nucleus in Beef Tissues' • ' 



constancy of the DNA content of the nucleus in mammals as well as in 

 other groups of animals. Davidson et al.,^ studying the DNA content of the 

 nucleus in several tissues of the fowl, confirmed that the amount of DNA per 

 nucleus was constant in cells from the organs examined (Table III). 



The results of the different authors who have studied chemically the DNA 

 content of the nuclei of various tissues from the same animal are shown in 

 Table IV. These results are, in general, in good agreement with the Boivin- 

 Vendrely theory of the constancy of DNA in diploid somatic nondividing 

 nuclei within the same species, this amount being double that found in ha- 

 ploid cells (sperm) in the same species. The striking relationship between the 

 DNA content of the nucleus and the number of chromosomes is clear from 

 this table. 



