102 OUTLINES OF NATURAL HISTORY. 



the " breast-bone " (h). Behind the true bcack comes that 

 portion of the backbone which is known as the " loins " 

 (/), which is followed by a portion which is enclosed between 

 the two haunch-bones (i). Finally, there is the long and 

 slender portion of the backbone which constitutes the 

 " tail " (c). 



The fore-limb is connected with the trunk chiefly by 

 means of the " shoulder-blade " {sc), followed below by 

 the strong and single bone of the upper arm (A). This is 

 succeeded by two bones which constitute the fore-arm (/), 

 and these carry a number of little bones which make up the 

 wrist-joint (ca). The palm of the hand {m), as already 

 remarked, is carried off the ground, and the hand finally 

 terminates in five fingers, or rather toes. 



The hinddimb is connected with the trunk by means of 

 the haunch-bone (i), which carries the upper bone of the 

 leg or "thigh-bone" {fe). Below this are the two bones 

 which constitute the shin (<), and these carry the small 

 bones of the ankle (ta). The instep and sole of the foot 

 {m) are raised completely off the ground, and the foot ter- 

 minates in four toes. 



As regards the digestive system of the Dog, the jaws, as 

 we have seen, are armed with teeth ; but these teeth are 

 intended for cutting and not for bruising or grinding 

 down the food. The Dog, therefore, cannot be said to 

 chew or " masticate " its food, but it swallows its food in 

 separate mouthfuls which it simply tears or cuts off with 

 its sharp teeth. Salivary glands (Latin, saliva,^ spittle) 

 pour their secretion into the mouth, thus facilitating swal- 

 lowing ; and the tongue, unlike that of the cat, is quite 

 smooth instead of being prickly. The mouth opens into 

 a gullet, the gullet into a capacious stomach, and the 

 stomach into an intestine, but the last is comparatively 

 short as compared with the intestine of vegetable-eating 

 quadrupeds. The intestine also receives the secretions of 

 two large digestive glands — namely, the liver and the 

 "sweetbread" or "pancreas" (Greek, pan, all; hreas, 

 flesh) — both of which produce fluids which exercise an 

 important influence on the food. 



