52 
ISLAND LIFE. 
[part I. 
The only outlying portions of the region about which there 
can he any doubt are — Central America, or that part of the 
region north of the Isthmus of Panama, the Antilles or West 
Indian Islands, and the temperate portion of South America 
including Chili and Patagonia. 
In Central America, and especially in Mexico, we have an 
intermixture of South American and North American animals, 
but the former undoubtedly predominate, and a large proportion 
of the peculiar Neotropical groups extend as far as Costa Rica. 
Even in Guatemala and Mexico we have howling and spider- 
monkeys, coati-mundis, tapirs, and armadillos ; while chatterers, 
manakins, ant-thrushes, and other peculiarly Neotropical groups 
of birds are abundant. There is therefore no doubt as to Mexico 
forming part of this region, although it is comparatively poor, 
and exhibits the intermingling of temperate and tropical forms. 
The West Indies are less clearly Neotropical, their poverty 
in mammals as well as in most other groups being extreme, 
while great numbers of North American birds migrate there 
in winter. The resident birds, however, comprise trogons, 
sugar-birds, chatterers, with many humming-birds and parrots, 
representing eighteen peculiar Neotropical genera ; a fact which 
decides the region to which the islands belong. 
South temperate America is also very poor as compared with 
the tropical parts of the region, and its insects contain a con- 
siderable proportion of north-temperate forms. But it contains 
armadillos, cavies and opossums ; and its birds are all of 
American groups, though, owing to the inferior climate and 
deficiency of forests, a number of the families of birds peculiar 
to tropical America are wanting. Thus there are no manakins, 
chatterers, toucans, trogons, or motmots ; but there are abun- 
dance of hang-nests, tyrant-bird3, ant-thrushes, tree-creepers, 
and a fair proportion of humming-birds, tanagers and parrots. 
The zoology is therefore thoroughly Neotropical, although 
somewhat poor ; and it has a number of peculiar forms as the 
chinchillas, alpacas, &c., which are not found in the tropical 
regions except in the high Andes. 
Comparison of Zoological Regions with the Geographical 
Divisions of the Globe— Having now completed our survey 
