viii INTRODUCTION. 



All the CanidcB, the habits of which are known, either make use of 

 burrows which they themselves excavate, the deserted burrows of other 

 animals, caves or cavities amidst rocks, or hollow trees. The burrows 

 may be quite solitary, or so associated as to form a sort of underground 

 canine village. 



A litter generally consists of from three to a dozen young, which, so 

 far as known, are brought forth blind, as in the Domestic Dog. The 

 period of gestation is supposed to vary within narrow limits from 

 about sixty-two to sixty-eight days. 



The mammary glands are from six to ten in number, but the varia- 

 tion which is found in the Domestic Dog as regards this character may 

 lead us to anticipate that it may not be a constant one in wild species. 



There is no doubt that species universally ranked as distinct such 

 as the Wolf and the Jackal can produce hybrids ; but we have no 

 evidence of the fertility of such hybrids inter se. Hybrids between the 

 Dog and the Wolf on the one hand,, and the Dog and the Jackal on the 

 other, have, however, been proved to be thus fertile, though for no 

 long period. 



GEOGRAPHICAL DISTRIBUTION. 



As we have said, the wild Canidce are distributed over the greater 

 part of the habitable globe. In the Old World they are found from 

 Spitzbergen and Siberia to the Cape of Good Hope and Java. 



In the New World they are to be met with from the shores of the 

 Arctic Ocean to Tierra del Fuego and the Falkland Islands. The far 

 greater number of kinds twenty of our list of species are found 

 in the Northern Hemisphere, while only twelve are peculiar to regions 

 south of the equator, three at the least being common to both. 



Certain regions of the world are conspicuous from the circumstance 

 that none of the Canida inhabit them except the Dingo, which has 

 probably been introduced by man. We have included it in our list, 

 because we treat of existing Canidce, and it is now certainly to be 

 reckoned a wild form ; but if we exclude it, then in the whole conti- 

 nent of Australia, the vast island of New Guinea, with Tasmania, New 



