?i68 THE GOODNESS OP THE DEH'Y. 



stitutions, may rise up in new ones, whilst fresh soils reward 

 the cultivator with more plentiful returns. Thus the differ- 

 ent portions of the globe come into use in succession as 

 the residence of man ; and, in his absence, entertain 

 other guests, which by their sudden multiplication fill the 

 chasm. In domesticated animals we find the effect of their 

 fecundity to be, that we can always command numbers : 

 we can always have as many of any particular species as 

 we please, or as we can support. Nor do we complain of 

 its excess ; it being much more easy to regulate abundance, 

 than to supply scarcity. 



But then this superfecundity , though of great occasional 

 use and importance, exceeds the ordinary capacity of nature 

 to receive and support its progeny. AH superabundance 

 supposes destruction, or must destroy itself Perhaps there 

 is no species of terrestrial animals whatever, which would 

 not overrun the earth, if it were permitted to multiply in 

 perfect safety ; or offish, which would not fill the ocean : at 

 least, if any single species were left to their natural increase 

 without disturbance or restraint, the food of other species 

 would be exhausted by their maintenance. It is necessary, 

 therefore, that the effects of such prolific faculties be cur- 

 tailed. In conjunction with other checks and limits, ail sub- 

 servient to the same purpose, are the thinnings which take 

 place among anim-als, by their action upon one another. In 

 some instances we ourselves experience, very directly, the 

 use of these hostilities. One species of insects rids us of 

 another species ; or reduces their ranks. A third species 

 perhaps keeps the second within bounds : and birds or liz- 

 ards are a fence against the inordinate increase by which 

 even these last might infest us. In other, more numerous, 

 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 species ; 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 purposes there never are. Her species 

 never fail. The provision which was originally made for 

 continuing the replenishment of the world, has proved itself 

 to be effectual through a 1 )ng succession of ages. 



What further shows, that the system of destruction 

 amongst animals holds an express relation to the system of 

 fecundity ; that they are parts indeed of one compensatoi'y 



