40 



HELEN DEAN KING 



TABLE 16 



Shoioing the coefficients of variation, with their probable error, for the body weights 

 at different ages of inbred rats of the two series combined (A , B) separated into 

 three groups according to the generation to which the individuals belonged 



as several investigators have shown, albino rats from diverse 

 strains that are reared in various ways show pronounced dif- 

 ferences in their rate of growth, and presumably there is a corre- 

 sponding difference in the variability of their body weights at 

 different ages. 



Table 17 gives the coefficients of variation for body weights 

 at various ages of fifty male and of fifty female rats reared as 

 controls for the present inbred series. As already stated these 

 animals were a selected group taken from the same strain as the 

 inbred rats and reared under similar environmental conditions. 

 The coefficients of variation for stock rats given in table 17 are 

 reproduced from tables 4, 5 and 6 of a previous publication 

 (King, '15 a). 



