# 



% 





Mi-, mm^ 



PLATE IX. (A) Nucleus of Chlamydomonas showing the nuclear envelope (e) with its two membranes 

 and the dense granular nucleolus (n). The condensed structure at c probably represents a part of 

 a chromosome in longitudinal section. 40,000 X- (Courfesy of R. Soger and G. E. Palade.) (6) 

 Nucleus of an endothelial cell (rat) with chromosomes condensed and located mainly near the nu- 

 clear envelope. Note at c a centriole sectioned almost transversely. 34,000 X- (Courfesy of G. E. 

 Palade.) 



