THE GROWTH OF GROUPS 



43 



the two are satisfactorily shown in Fig. i, which represents 

 the upper surface of the skull and the sole of the hind 

 foot of both kinds. The fur is bristly and dark greyish 

 brown in colour, it is less variable in respect of the latter 



M. rattus. G, bengalensis. 



FIG. i. x o. 



quality than is the fur of the house rat. Albino, yellow, 

 and black varieties were found but rarely. White-bellied 

 ones were never found. 



The zoologist wishes to answer the following questions. 

 What is the present state of the animal kingdom or any 

 defined portion of it at the moment ? How did the whole 



