42 Introduction to Animal Morphology. 



tions, do not give the maximum of possible work, 

 bringing them first to the condition of rudimental 

 organs, and then causing their complete obsolescence. 



CHAPTER VII. 



DISTRIBUTION OF ANIMALS. 



ANIMALS exist almost everywhere on the globe. Each 

 form has a more or less extensive area. As a rule, 

 synthetic and generalized types have the most limited 

 ranges. Correlations in distribution are also notice- 

 able, and hence the surface of the globe may be 

 divided into provinces, each characterized by its own 

 peculiar fauna. These provinces may be combined 

 into larger tracts or regions, of which there are 

 seven : ist. Palsearctic, or the northern half of the 

 Old World. 2nd. Nearctic, or America north of 

 Mexico. 3rd. Neotropical, or Central, and South 

 America (except Patagonia). 4th. Ethiopian, or 

 Africa south of the Sahara. 5th. Indian and 

 Malayan. 6th. Australian, or Australia and that part 

 of the East Indian Archipelago south-east of the 

 deep-sea boundary line pointed out by Mr. Wallace. 

 yth. Antarctica, or the region about the South Pole. 



The provinces included here are as follows : In the 

 Palcearctic ist. The Eastern Polar, characterised by the pre- 

 sence of the Reindeer, Lemming, Wolf, Arctic Fox, and many 

 Mustelines, Salmonidae, Auks, Divers, and Gulls ; and at its 

 southern limit Grouse and Surnia, the land Molluscs, Limax, 

 Arion, &c. 2nd. The Middle European, extending to the 



