118 NATURAL THEOLOGY. 



fence against the ordinate increase by which even 

 these last might infest us. In other, more nume- 

 rous, and possibly more important instances, this 

 disposition of things, although less necessary or 

 useful to us, and of course less observed by us, 

 may be necessary and useful to certain other spe- 

 cies ; or even for the preventing of the loss of cer- 

 tain species from the universe : a misfortune which 

 seems to be studiously guarded against. Though 

 there may be the appearance of failure in some 

 of the details of Nature's works, in her great pur- 

 poses there never are. Her species never fail. 

 The provision w hich was originally made for con- 

 tinuing the replenishment of the world has proved 

 itself to be effectual through a long succession of 

 ages. 



What further shows, that the system of destruc- 

 tion amongst animals holds an express rp.lation to 

 the system of fecundity, — that they are parts in- 

 deed ot one compensatory scheme, — is, that m 

 each species the fecundity bears a proportion to 

 the smallness of the animal, to the weakness, to 

 the shortness of its natural term of life, and to the 

 dangers and enemies by which it is surrounded. 

 An elephant produces but one calf; a butterfly 

 lays six hundred eggs. Birds of prey seldom pro- 

 duce more than two eggs ; the sparrow tribe, and 

 the duck tribe, frequently sit upon a dozen. In the 

 rivers, we meet with a thousand minnows for one 

 pike ; in the sea, a million of herrings for a single 

 shark. Compensation obtains throughout. De- 



