146 
JOUKNAL OF MAMMALOGY 
RECENT LITERATURE 
Hinton, Martin A. C. Report on the House Rats of India, Burma, and 
Ceylon. Journ. Bombay Nat. Hist. Soc., vol. 26, pp. 59-88, December 20, 1918, 
and pp. 384r-416, May 20, 1919. 
After studying the very large series of house rats obtained by the Mammal 
Survey of India together with the Indian material in the British Museum Mr. 
Hinton concludes that of the 21 known Indian, Burmese and Ceylonese forms no 
less than 17 (12 new) are subspecies of Rattus rattus. His general observations 
on these subspecies are of unusual interest. “Turning now to India,” he says 
(pp. 65-68) “the rats listed in the Survey Reports as ‘rufescens,^ or ‘rufescens 
va,T.\ afford us with problems of considerable complexity. In the first place, 
although I am unable to find any character in the dentition, skull, or external 
parts, to distinguish any of them satisfactorily from R. rattus, the range of vari- 
ation is enormous. Indian skulls with well worn teeth have the condylo-basal 
length ranging between 34 and 44 mm. The fur may be long, soft, dense and 
without spines; or it may be short, thin, and harsh, with numerous spiny bristles. 
The dorsal colour varies between bright rufous, or warm olivaceous tints on the 
one hand, to dull tawny, or cold mixtures of black and grey on the other. The 
underparts may be pure white or pale lemon; or they may be slaty, with or 
without a rusty tinge or bloom. The hands and feet may be white or yellowish 
above, with or without dusky markings; or they may be wholly blackish brown 
in colour. The mammary formula may be 2-3=10 or 3-3=12. Every inter- 
mediate stage between the extremes indicated may be found in the collections 
before me. Nevertheless, much of this variation has a definite geographical 
value; and where long series are available from one locality or district, the rats 
are usually found to conform closely to one or more definite local types. It is 
therefore possible to define a considerable number of local races or subspecies. 
The members of the rattus group seem to afford an exception to the rule, so 
general for wild mammals, that not more than one subspecies of a given species, 
or not more than one of two or more very closely allied species can inhabit a 
given locality. But these rats are capable of playing many parts in warm coun- 
tries; thus we find them following a free life in fields and hedgerows, far from 
houses, or high up among the branches of trees in forests; or they may lead a 
purely parasitic existence in human habitations or shelters. It is a poor sort of 
locality which refuses at least two “niches in nature” for rattus; and the semi- 
domesticated stocks, at all events, of this species have frequent opportunities 
for prospecting and touring conferred upon them by railways, wheeled carriages, 
and shipping. 
Like other murines, this species shows, within certain limits, an almost start- 
ling plasticity. Its structure responds readily to the demands of purely local 
requirements. If necessary colour or the quality of the coat are modified; a 
change in diet induces modifications in the development or the “set” of the 
muscles of mastication; and these in turn mould the skull, or lead to the length- 
ening or shortening of the tooth-rows. 
Considerations such as those mentioned in the preceding paragraphs lead us 
to realize the hopelessness of attempting to disentangle the history of the rats in 
large towns or ports like Calcutta or Bombay. In such places the rat population 
