SCIENTIFIC REtSULTS FROM THE MAMMAL SURVEY. 3f3 



are greyish white in most, but sometimes they are lightly tinged 

 with yellow. The tails are dark and tinicoloured. 



In 5 of the specioiens from Taknla (H. & B. 144-171) the backs 

 are much darkened by numerous black hairs. One of them, No. 

 384G (H. & B. 161), has a pale line, convex backwards, curving 

 across the shoulders and looking as though it had been produced by 

 a bleaching of the hair tips ; another No. 384 (H. & B. 170) is 

 noticeably paler over the head and shoulders than behind. No. 

 3855 (H. & B. 179), the largest specimen of this series, is paler 

 than any of the others and as regards colour falls well into line 

 with the Lohaghat series. 



All the specimens from Kumaon, except those mentioned below, 

 are soft furred rats and although they vary locally to some extent 

 in colour and size they are all clearly referable to one subspecies. 

 In working through the collection I have received the impression 

 that the dorsal coloration of adults passes regularly through the 

 following seqiTence of changes : — the backs are at first dull greyish 

 black ; then the ground colour changes from cold grey to bright 

 yellow and the blackness of tht? long hairs appears to become more 

 intense ; next bleaching of the hair tips starts on the head on 

 shoulder, and the black hairs apparently become confined to the 

 rump ; lastl}^ the bleaching extends over the whole dorsal 

 surface which tends to become of a uniform yellow-brown. 

 Some such sequence of changes seems to apply to other subspecies 

 also, e.g., arhoreus and narhadw. 



It is very difficult to decide whether these changes are connected 

 simply with growth and advancing age, or whether they follow 

 upon each renewal of the coat. I can only leave the matter to 

 future investigation with the following inconclusive statement : — 

 The occasional occurrence of small rats with yellow-brown backs 

 and of large, and in some cases undoubtedly very old, rats with 

 cold grey tints seems to imph' that these changes take place as 

 often as the coat is renewed and therefore that the cycle is repeat- 

 ed often in the life-time of the individual. On the other hand the 

 whole collection before me shows clearly enough that cold grey 

 and yellow-brown are the prevailing tints of small and large rats 

 respectively. 



The specimens collected by Mr. Crump at Khati and Lwarkhet, 

 the two highest stations at which rats of this species were found, 

 are of great interest. They are distinguished from those of most 

 of the lower stations by having short, harsh and sometimes spiny 

 fur. The dorsal colour is a warm brown, about as in brighter 

 examples of " rvfescens". The bellies are white or yellowish ; 

 and in some specimens many of the rather long and rough ventral 

 hairs have slaty bases. The feet are light brown with occasional 

 dusky markings. The skulls are noticeably smaller than in typical 



