CHAPTER XV 

 CARNIVORES continued 



THE DOG TRIBE 

 Family CANID^ 



UNDER the general title of Dogs may be included all the animals commonly 

 known as wolves, jackals, foxes, and wild dogs, together with the various breeds of 

 domestic dogs. These collectively constitute the family Canidce, and form a group 

 in some respects intermediate between the Carnivores treated in the two preceding 

 chapters, and those described in the three succeeding ones. The Dog family must 

 always have an especial interest, since it includes the animals which have become 

 more thoroughly the friends and companions of man than any other creatures. The 

 origin of the domestic dogs is, however, shrouded in the mist of antiquity, and it 

 is still an open question whether the various breeds are descended from a single wild 

 stock, or whether they are the product of several species. 



The Dog family, as thus constituted, forms, at the present day, a compact and 

 well-defined group, the wild members of which cannot be confused with those of any 

 other. The whole of them are characterized by their long and pointed muzzles, 

 their moderately long tails, and their perfectly digitigrade feet furnished with blunt, 

 nearly straight, and nonretractile claws. Then, again, all the dogs have but four 

 toes on the hind-feet, while, with the exception of the African hunting-dog, the 

 number of toes on the fore-feet is five, of which the first, or innermost, is shorter 

 than either of the others, and does not touch the ground. The limbs, although vary- 

 ing in relative length, are never so short in proportion to the body as is the case in 

 so many of the Civet family. The ears are pointed and erect, but vary greatly in 

 length in the different groups. Such are some of the chief external characteristics 

 of the dogs, but, in order to understand their distinction from other families of 

 Carnivores, it is essential to pay attention to the skull and teeth. In all the dogs the 

 skull, as shown in the figure on p. 355, is characterized by its elongated muzzle and 

 the large number of teeth with which it is furnished ; in both of which respects it is 

 widely different from the skull of the cats. On the under surface of the hinder part 

 of the skull the tympanic bulla is inflated and bladder like, although it is not divided 

 into two chambers by a complete septum. This part of the skull serves, there- 

 fore, to distinguish the dogs from the Carnivores yet mentioned, with the exception 

 of the hyaenas. From the hyaenas, as well as from the cats, the dogs are read- 

 ily distinguished by the number and structure of their teeth. With but few 

 exceptions, the total number of their teeth is forty-two, or two more than the 

 true civets ; the series consisting of f incisors, \ canines, premolars, and f molars. 

 (496) 



