312 A. FRANKLIN SHULL 



Relative volume of nuclei in oocytes of young adult 



females .065 ± .0072 



In middle-aged females .051 ± .0033 



In old females 0.057 ± 0.0042 



These means and high probable errors seem to indicate that there 

 is no relation between age and relative nuclear volume in the 

 oocytes. The largest difference of means, that between young 

 and middie-aged females, is less than twice as great as its probable 

 error. 



It is not possible to determine whether the absolute sizes of the 

 cells are different at different ages, for the reason that these cells 

 change so much in size during their growth stages. I incline to 



TABLE 8 



Relative nuclear volumes of the yolk gland, stomach-intestine and oocytes of Hydatina 



senta reared in spring water and in manure solutions 



Yolk gland 



Stomach-intestine . 

 Oocytes 



RELATIVE NUCLEAR YOLUME 



Spring water 



0.718±0.0105 

 0.069 ±0.0029 

 0.070±0.0048 



Manure solution 



0.709±0.0119 

 0.079 ±0.0028 

 0.066 ±0.0039 



the opinion that all of the irregularity of the results shown above 

 are due to this growth, rather than to any fundamental changes 

 which the statistics are incapable of revealing. 



EFFECT OF MANURE SOLUTION 



The relative nuclear volumes of cells in animals of the same age, 

 some of them reared in spring water, others in manure soution, 

 as described in the introduction, are given in table 8. The results 

 from all three of the tissues studied are combined in one table. 



The differences in the yolk gland and oocytes are negligible. 

 The values for the relative nuclear volume in the stomach-intestine 

 are, however, such that, by the usual statistical standards, they 

 must probably be regarded as significant. To determine the 

 route by which the relative increase of the nuclei in manure solu- 



