392 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vtl. XX VL 



for each locality, while noticeably differing from that of other 

 stations". This is perfectly true. But on studying these rats 

 closely it becomes apparent, moreover, that at each locality the 

 coloration of the adult pelage is affected by a series of changes, 

 which, whether produced by gradual replacement of hairs, by bleach- 

 ing, or by a combination of both processes, seems to be intimately 

 connected with growth or size. Observations lead me to think 

 that similar changes take place continuously in all the Indian sub- 

 species of R. rattus. 



In the series from Kamnagar a transition from a younger cold 

 grey pelage, with numerous black hairs, to an older, brighter and 

 yellow pelage may be observed. In 6 small rats (H. & B. 139- 

 155) the tails are short, fine-scaled and slightly paler below than 

 above ; the feet in 1 show a faint dusky mark, but in the others 

 they are quite white above. In 6 large rats (H. & B. 164-177) 

 the black hairs are rather abundant along the spines, but less 

 numerous towards the flanks ; in these the ground colour varies 

 from grey, through brown, to light yellow, but it is always distinct- 

 ly warmer in tone than in the dark bellied " rnfescens " from this 

 locality. In 3 of the large specimens the hairs on the chest and 

 mid-ventral line have slaty bases and more or less evident buff tips. 

 The feet are whitish in all ; and purest in those specimens in which 

 all the ventral hairs are white throughout. 



In all the specimens from Sitabani the fur is soft and long ; the 

 bellies pure white, save for a small spot on the chest where, in 

 several individuals, the hairs have slaty bases. In 6 (H. & B. 138- 

 152) the dorsal ground colour is greyish yellow and is rather exten- 

 sively darkened by black hairs ; in all the feet are white above 

 without dusky markings. No. 3971 (H. & B. 157), with mode- 

 rately worn teeth, has the back and feet as in the small or imma- 

 ture specimens. No. 3986 (H. & B. 164) has rather more yellow 

 and less black on the back and its feet show a faint dusky mark. 

 No. 3969 (H. & B. 166) is still brighter and the dusky 

 mark, particularly on the right foot, is more distinct. Lastly No. 

 3987 (H. & B. 187), a very old specimen, has the back of a cold 

 grey mottled with a good deal of gre^dsh black ; the feet show a 

 distinct dusky stripe above. 



The long series from Lohaghat is really very uniform. The 

 ground colour of the back varies between greyish and yellowish 

 brown, more or less darkened along spine and over the rump by 

 black hairs ; the latter show some tendency to form a median 

 stripe towards the tail-root. The under-parts are usually pure 

 white to the hair bases, but a small chest spot of slaty based hairs 

 is frequently present. In several there are faint indications of a 

 mid-ventral stripe of buff; and in some of the specimens the whole 

 ventral surface is suffused with pale lemon or bright buff. The feet 



