252 M. Marcel de Serres on the Distinctive Characters 



berculous teeth of the fox exhibits symmetrical excavations 

 more deep and decided than in the dog and the wolf, so that 

 those of the upper and lower jaw very accurately correspond in 

 their indentations. From this arrangement it follows that the 

 mastication of the food should be much more complete in the 

 fox than in any of the other two animals with which we are now 

 comparing it. 



We have another observation to make relative to the tuber- 

 culous teeth of the lower jaw ; — the last, or smallest, placed be- 

 hind that one which is next to the carnivorous tooth is never 

 wanting in any jaw-bone in the wolf. On the contrary, this 

 tooth is often wanting in the lower jaw of the dog and fox. 

 Sometimes it exists in certain individuals, and in others there is 

 no trace of it ; sometimes it may be seen in one side of the jaw 7 , 

 whilst there is no trace of it in the other. Such anomalies are 

 never noticed in the wolf ; so that the presence of all the tuber- 

 culous teeth in lower jaws, of which fragments only are obtained, 

 is a presumption that they belong to the wolf. 



Respecting the maxillary bones, whether superior or inferior, 

 they are proportionally much shorter in the dog than in the 

 wolf and fox. This character is evident even in those races of 

 the dog which are largest in size, and most devoid of intelligence. 

 The lower jaw, especially, is stronger, thicker, and fuller in the 

 dog than in the wolf. It is also more arched towards its base, 

 which is most strikingly witnessed when the several heads are 

 placed upon the same horizontal plane. In this way it may 

 easily be perceived, that, whilst the inferior edge of the jaw in 

 the dog describes a curved line, this line is almost horizontal in 

 the wolf, and slightly bent in the fox. Hence it follows that 

 the elevation or the height of the sides of this jaw-bone from its 

 base to the alveolar border is greater in the dog than in the wolf 

 or fox. 



If we place, in the position already indicated, on a hori- 

 zontal plane, the head of a dog, and measure the height of 

 the head by drawing a line from the posterior part of the 

 backmost molares, or the tuberculous teeth, perpendicular- 

 ly to the forehead, it will easily be observed that its height, 

 other proportions being in keeping, is much more considerable 



