234 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



broad, flattened spatula-shaped tip. At either side of the middle line 

 toward the root of the tongue is a very large compound circumvallate 

 papilla (Figs. 82 and 83). In the ox the tongue is pointed, thicker, and 



Fig. 84.— The " Parrot-Mouth" Malformation of the Horse's Mouth. (Gamgee.) 



deeper, and with two diverging rows of papillse, each containing from 

 eleven to thirteen papilloe, at the base of the tongue. 



In the horse the sensitive and mobile upper lip is the main organ in 

 the collection of food. The nose, aided by the sense of touch, serves to 

 indicate the substances suitable for food ; the upper lip serves to carry the 

 food between the incisor teeth, so that it may be firmly held, while by an 



active jerk and twisting motion of the 

 head the grass is cut, ha}' pulled from 

 the rick, or branches severed. In stall- 

 fed animals loose food is taken from 

 the manger by the lips, aided by the 

 tongue. If the incisor teeth are badly 

 formed, as in the projection of the upper 

 incisor teeth over the lower, as in the 

 malformation termed " parrot-mouth," 

 grazing will be prevented (Fig. 84). So 

 also swelling of the gums or of the 

 palate, as in dentition, may act as a 

 mechanical impediment to the action of 

 the incisor teeth and prevent grazing 

 (Fig. 85). The position assumed by 

 the grazing horse is characteristic. The fore legs are separated, one 

 fore leg usually being advanced, or may be flexed, since the neck is not 



Fig. 85.— Prehensile Extremity of 

 the Jaws of the Horse. (Colin.) 



