52 



ISLAND LIFE. 



[part I. 



The only outlying portions of the region about which there 

 can be 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-birds, 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 Geogra/phicol 

 Divisio7is of the Globe. — Having now completed our survey 



