1909.] R. E. IvLOYD : Fertility and Normality in Rats. 



263 



rat can be counted with ease and without possibihty of mistake, 

 indeed the figures themselves are a proof of their own accuracy for 

 the work was carried out at the two places by independent obser- 

 vers. In the tables the vertical column of figures on the left 

 represents the approximate weights of the rats, the highest horizon- 

 tal row of figures represents the number of the 3^oung which a 

 female rat may carry, the other horizontal rows of figures show the 

 numbers of rats of a particular weight which carry a particular 

 number of young. Thus, in the case of table 1 the second row of 

 figures shows that out of 1,003 r^ts which were examined, only 5 

 were nearly of fifty grammes weight , and that of these 3 carried 

 five 3^oung, while the other 2 carried four and six respectively. It 

 is plain that the rats of Poona are smaller than the rats of Belgaum, 

 otherwise they resemble one another. Both races, if they should 

 be called separate races, possess skulls of the Mus rattus type. 



-Observations made at Poona 



