300 NATURAL THEOLOGY. 



derstood, we have considered this business of com- 

 pensation under ceriSim jmi^ticulaj'ities of constitu- 

 tution in which it appears to be most conspicuous. 

 This view of the subject necessarily limits the in- 

 stances to single species of animals. But there 

 ai'e compensations, perhaps not less certain, wiiich 

 extend over large classes and to large portions of 

 livinsf nature. 



I. In quadrupeds, the deficiency of teeth is usu- 

 ally compensated by the faculty of rumination. The 

 sheep, deer, and ox tribe are w^ithout fore-teeth in 

 the upper jaw.""^ These ruminate. The horse 

 and ass are furnished with teeth in the upper jaw, 

 and do not ruminate. In the former class, the 

 grass and hay descend into the stomach nearly in 

 the state in which they are cropped from the pas- 

 ture or gathered from the bundle. In the stomach 

 they are softened by the gastric juice, which in 

 these animals is unusually copious : thus softened 

 and rendered tender, they are returned a second 

 time to the action of the mouth, where the grind- 

 ing teeth complete at their leisure the trituration 

 which is necessary, but which was before left im- 

 perfect : I say the trituration which is necessary ; 

 for it appears from experiments that the gastric 

 fluid of sheep, for example, has no effect in digest- 

 ing plants unless they have been previously masti- 

 cated ; that it only produces a slight maceration, 

 nearly as common water v/ould do in a like de- 



^7 See the account of the teeth, in the Appendix. 



