CLASS MAMMALIA. 



lOI 



c) are very long and pointed, and tlieir special function is 

 to act as weapons of offence and defence, and also to kill 

 the animals upon which the Dog feeds. Outside the can- 

 ine teeth, again, are situated the teeth which are known 

 commonly as the back teeth or "grinders," and which are 

 technically called the "molars" (Latin, mola, a mill). 

 The molar teeth (fig. 45, m) of the Dog are twelve in 

 number in the upper jaw (six on each side), and fourteen 

 in number in the lower jaw (seven on each side). They 

 can, however, only very partially be called "grinders," 

 with any propriety, since all but the last two on each side 

 of each jaw have sharp edges adapted for cutting and 

 dividing flesh. 



The skiill is united to the backbone behind by two 

 joints. The first part of the backbone (fig. 46, n), imme- 



Fig. 46.— Skeleton of the Dog (after Youatt). s Skull ; n Neck ; d Back ; I 

 Loins; e Tail; &c Shoulder-blade; h Bone of the upper arm ; /Two 

 bones of the fore-arm ; ca Bones of the wrist ; m Palm of the hand ; i 

 Haunch-bone ; /e Thigh-bone ; t Bones of the shank or shin ; ta Bones 

 of the ankle ; m Sole of the foot ; r Ribs ; 6 Breast-bone ; p Ligament 

 supporting the head. 



diately behind the head, constitutes the neck, and is com- 

 posed of seven joints. The next portion of the backbone 

 constitutes the back properly so called, and the different 

 joints or " vertebra " here carry the ribs (r). The ribs 

 form the walls of the chest, protecting the heart and lungs, 

 and they are connected in front mth the bone known as 



