TOO THE GROWTH OF GROUPS 



feet was more striking than their unusual colour, for the 

 same tint may be seen occasionally in other sports and 

 species. 



Appearances are more or less surprising according as 

 they are more or less rare. This particular colour is not 

 very rare, it has been seen occasionally among rats of other 

 species. The following cases may be mentioned. Two 

 mole-rats (G. bengalensis) captured together in Calcutta 

 a M. mttus from Dacca and another from Calcutta ; also 

 some specimens of M. concolor in Rangoon. The colour 

 in question is seen in many other animals, notably in 

 the commonest variety of ferret. Yellow is perhaps the 

 technical term for it, but tow-coloured is more descriptive. 



Cases of wide variation in foot length are also occa- 

 sionally met with in other species. Twenty-two mole- 

 rats were obtained from one field in Purneah, two of them 

 will be referred to. As regards length of head and body 

 they are very nearly alike. The hind foot of one, an old 

 male, is 35 mm. in length ; that of the other, a more 

 lightly built female, is only 26 mm. The difference in 

 outward appearance is most striking ; the females of 

 the species are not small footed as a rule. There is of 

 course no evidence to show that either animal was the 

 founder of a large or a small-footed group, the case is 

 only mentioned in order to illustrate the great differences 

 in foot length that may occur in the same community of 

 rats. 



In reviewing this case we are again face to face with 

 the question how is it that each of the three individuals 

 combines in its person the two separate peculiarities of 

 colour and foot length ? Again there appears to be only 

 the one answer, because they are of the same lineage 



