Z 10 



THE OOCYTE 



OOCYTE DIAMETER (micro) 



50 100 



CONCENTRATION 



TOTAL AMOUNT 

 OF RNA IN ^^'♦-2-— \ OF RNA IN 



NUCLEOLUS 



SOLUBLE RNA 

 IN NUCLEOLUS 



h 



DIAMETER OF NUCLEOLUS 



INCREASE OF 



CYTOPLASMIC VOLUME 



OVER NUCLEAR VOLUME 



OOCYTE DIAMETER (micro) 



Fig. 2. 

 n'owth of 



A comparison of some of the changes in nucleolar RNA and the 

 the oocyte. (Data from Figs. 1 and 3.) 



plasmic contribution to cell size increases markedly. This is indi- 

 cated by the break in the slope of the curve for the nucleus in 

 Fig. 1. The diameters of the nucleolus and the oocyte increase 

 proportionately until the latter attains about one-half its mature 

 size, when all growth ceases (curve for the nucleolus in Fig. 1). 



RNA Content of Individual Nucleoli 



Some measurements on the RNA content and concentration of 

 individual nucleoli are pertinent in this regard. The ultraviolet 

 absorption of nucleoli isolated in distilled water was compared 



