36 
ZOOLOGICAL GEOGRAPHY. 
[part III. 
It is doubtful whether mammals or batrachians have any means 
of passing, independently of man’s assistance ; the former having 
but one doubtfully indigenous representative, the latter none at 
all. The remarkable absence of all gay or conspicuous flowers 
in these tropical islands, though possessing a zone of fairly 
luxuriant shrubby vegetation, and the dependence of this phe- 
nomenon on the extreme scarcity of insects, has been already 
noticed at Yol. I. p. 461, when treating of a somewhat similar 
peculiarity of the Hew Zealand fauna and flora. 
7. South Temperate America , or the Chilian Sub -region. 
This sub-region may be generally defined as the temperate 
portion of South America. On the south, it commences with the 
cold damp forests of Tierra del Fuego, and their continuation up 
the west coast to Chiloe and northward to near Santiago. To the 
east we have the barren plains of Patagonia, gradually changing 
towards the north into the more fertile, but still treeless, pampas 
of La Plata. Whether this sub-region should be continued across 
the Eio de la Plata into Uruguay and Entre-rios, is somewhat 
doubtful. To the west of the Parana it extends northward over 
the Chaco desert, till we approach the border of the great forests 
near St. Cruz de la Sierra. On the plateau of the Andes, how- 
ever, it must be continued still further north, along the “ paramos” 
or alpine pastures, till we reach 5° of South latitude. Beyond this 
the Andes are very narrow, having no double range with an inter- 
vening plateau; and although some of the peculiar forms of the tem- 
perate zone pass on to the equator or even beyond it, these are not 
sufficiently numerous to warrant our extending the sub-region to 
include them. Along with the high Andes it seems necessary to in- 
clude the western strip of arid country, which is mostly peopled 
by forms derived from Chili and the south temperate regions. 
Mammalia . — This sub-region is well characterised by the pos- 
session of an entire family of mammalia having Neotropical 
affinities — the Chinchillidae. It consists of 3 genera — Chinchilla 
(2 sp.), inhabiting the Andes of Chili and Peru as far as 9° south 
latitude, and at from 8,000 to 12,000 feet altitude ; Lagidkm 
(3 sp.), ranging over the Andes of Chili, Peru, and South Ecuador, 
