78 MOUNTAIN FAUNAS 
tain barrier. Its presence is thus an indication that 
mountains do not necessarily form a barrier to dis- 
tribution, even to animals reputed to be so sensitive to 
cold as monkeys. 
The macaques also include one mountain form, 
Macacus tibetanus, which seems to occur in much the 
same region as the Tibetan langur, and also extends 
into China proper, in Sechwan and the south of Kansu. 
The narrow and broken mountain chains of this region, 
according to recent observers, have a damp climate, 
quite different from that of Tibet proper, and into the 
valleys the monsoon forest insinuates itself, taking 
with it part of its characteristic fauna, notably the 
two monkeys named. The macaques differ from the 
langurs in their diet, for they eat insects and other 
forms of animal food in addition to fruits and seeds. 
As this food is much more portable than leaves, they 
have cheek-pouches in which it may be stored, these 
being absent in the langurs, which have large saccu- 
lated stomachs, comparable to the stomachs of some 
ungulates. 
The Himalayan and Tibetan langurs and the Tibetan 
macaque appear to exhaust the members of the Primates 
which haunt mountains. None of the New World forms 
seem to be specially fitted for life at high altitudes, 
and though some of the African baboons inhabit rocky 
regions at some elevation, none seem to be peculiar to 
high mountains or plateaux. 
The insectivores have various mountain representa- 
tives, some showing peculiarities of distribution. The 
Alpine shrew (Sorex alpinus) inhabits the upper parts 
of the lofty mountain regions of Central Europe ; the 
Himalayan swimming shrew (Chimarrogale himalayica) 
inhabits the lower slopes of the Himalayas, where it 
