THE CANID.E, OR DOGS. 277 



ordinary development of these tusks, the length of 

 which finally may have prevented their opening 

 their jaws sufficiently. In answer to this it can 

 only be said that a bad hypothesis is better than 

 none. The sabre-toothed tiger appears and dis- 

 appears in the Miocene deposits both of the Old 

 and the New World. 



Pseudizlurua was shown above to be an inter- 

 mediate form between the weasel and the cat. 

 This does not exclude other intermediate forms. 

 One of these is the sElurogale, also the size of a 

 tiger and found in great abundance in the phos- 

 phate of Quercy. Its upper jaw resembles that of 

 Cats, the lower jaw shows the teeth of the Muste- 

 lidse (weasels and otters). The races arrange them- 

 selves in such a manner that, notwithstanding the 

 extraordinary variations in the size of the teeth- 

 in those which deviate most from the primary 

 form the lower jaw also has preserved the Cat 

 formula. 1 



1 We shall not refrain from pointing out the difficulty 

 which is met with in this apparently simple line of descent. 

 Of all the living Carnivora the Cats possess the most perfect 

 rudimentary clavicles, the others have either smaller traces of 

 these or none at all. All the ancestors of the Cats must at least 

 have possessed clavicles such as are still met with in the Cats. 

 And it is quite intelligible that the clavicles should have con- 

 tinued to exist in Cats, owing to their have retained the habit of 



