192 GEOGRAPHICAL ZOOLOGY. [PART iv. 



extensive group of animals, now almost extinct. Many of the 

 forms continue to exist only in islands, removed from the severe 

 competition of a varied mammalian population, as in Madagascar 

 and the Antilles ; while others appear to have escaped extermi- 

 nation either by their peculiar habits as the various forms of 

 Moles; by special protection as in the Hedgehogs; or by a resem- 

 blance in form, coloration, and habits to dominant groups in their 

 own district as the Tupaias of Malay which resemble squirrels, 

 and the Elephant-shrews of Africa which resemble the jerboas. 

 The numerous cases of isolated and discontinuous distribution 

 among the Insectivora, offer no difficulty from this point of view ; 

 since they are the necessary results of an extensive and widely- 

 spread group of animals slowly becoming extinct, and continuing 

 to exist only where special conditions have enabled them to main- 

 tain themselves in the struggle with more highly organized forms. 

 The fossil Insectivora do not throw much light on the early 

 history of the order, since even as far back as the Miocene 

 period they consist almost wholly of forms which can be referred 

 to existing families. In North America they go back to the 

 Eocene period, if certain doubtful remains have been rightly 

 placed. The occurrence of fossil Centetidae in Europe, supports 

 the view we have maintained in preceding chapters, that the 

 existing distribution of this family between Madagascar and the 

 Antilles, proves no direct connection between those islands, but 

 only shows us that the family once had an extensive range. 



Order IV. CAEN IVOR A. 



FAMILY 23. FELID^E. (3 Genera, 14 Sub-genera, 66 x Species.) 

 GENERAL DISTRIBUTION. 



The Cats are very widely distributed over the earth with 

 the exception of the Australian region and the island sub-region^ 



