34 



Nature of the Genetic Material 



10 



25 50 



DNA - F e u I g e n 



200 300 



Fig. 3a. Relative amounts of DNA in nuclei of salivary gland of Helix pomatia. 

 (From Swift, 1953; reproduced by permission of the author and the Academic 

 Press, Inc.) 



320 

 160 



eo 



< 40 

 Z 

 Q 20 



«*- 

 O 10 



^- 



o 



e 2JB 



< 



1.25 



.62Si- 



/ 





/ 





/ 



/ 



../« 



.. /. 



o gland 

 K fat 

 A duct 

 • aniage 



• •• 



10 



100 1000 



Nuclear Volume 



10000 



Fig. 3fc. Amount of DNA plotted against size of different polytene cell types 

 of Drosophila. (From Alfert, 1954; reproduced by permission of the author and 

 the Academic Press, Inc.) 



