528 THE MECHANICAL FUNCTIONS. 



skin over a great extent of surface. In the usual 

 state of the animal, this broad muscle appears on 

 the back (as represented in Fig. 219), contracted 



219 



into a thick oval disk, of which the fibres are 

 much accumulated at the circumference. From 

 the edges of this disk there pass down auxiliary 

 muscles towards the lower parts of the body ; the 

 action of which muscles tends to draw the skin 

 downwards, and to coil it over the head and paws, 

 in the manner shown in Fig. 220, like the closing 

 of the mouth of a great bag. 



10. Carnivora. 



THE type of the Mammalia may be considered 

 as having attained its full developement in the 

 carnivorous tribes, which comprehend the larger 

 beasts of prey. As their food is animal, they 

 require a less complicated apparatus for diges- 

 tion than herbivorous quadrupeds, possess greater 

 activity and strength, and enjoy a greater range 

 of sensitive and intellectual faculties. In ac- 

 cordance with these conditions we may notice 



