AGILE KANGAROO. 
109 
over the high grass ; when clmscil, it frequently seeks shelter 
in the thick beds of maugroves, passing over the muddy flats 
in such a manner as almost to baffle pursuit** 1 
In very many quadrupeds, the clothing consists of hairs of 
two kinds; the one which composes what I have termed the 
under fur, is very soft, often woolly, and generally more or 
less hidden by longer interspersed lmirs, which are of a harsher 
nature, and which may bo said to constitute an upper or 
outer fur. Sometimes the longer hairs assume the form 
of bristles, and even spines, (indeed all the different stages 
may be seen in the different species of Echimys , or spiny 
rats of South America, ns well ns in the Old World Rats.) 
In coses where the longer hair assumes the form of spines, the 
under fur is generally but little developed, and this under fur 
is almost always abundant in Mammals inhabiting cold 
climates, and in those which live on the summits of lofty 
mountains. It is generally abundant also in nocturnal species, 
and those which inhabit damp and swampy situations, or that 
live in the water, even though they arc denizens of a hot 
climate. On the other hand, the upper fur is often much 
developed in quadrupeds living in tropical climates: in the 
former cases the under fur is to protect the body from cold 
or wet, and in the latter, the long hair would appear to serve 
as a protection from the heat. Finally, I may remark, that 
the same animal exhibits great changes in the character of 
its fur when transported to different climates. 
Having observed that the character of the fur varies with 
the climate, wo are prepared to find Kangaroos, which, like 
the present species, or the M. anlilopinus , inhabit the most 
tropical portions of Australia, with the fur composed almost 
entirely of the coarser kind of hairs,—the under fur being 
very little developed. In these two species the fur is short* 
Gould's Monograph. 
