46 OF NUTRITION 



per circumftances for expanding and becoming 

 new individuals of the fame fpecies ; for, as all 

 parts of the body fend off organic particles fimilar 

 to thofe of which themfelves are compofed, the 

 refult of their union muft be the produdion of 

 new organized bodies fimiiar to the original. 

 Hence we may conclude, that this is the reafon 

 why organized bodies, during the time of their 

 growth and expanfion, are feldom or never ca- 

 pable of reproducing; becaufethe grovving parts 

 abforb the whole organic particles prefented to 

 them, and no furplus being fent from the differ- 

 ent parts of the body, propagation becomes, of 

 courfe, impradicable. 



This account of nutrition, and of reproduc- 

 tion, will not, perhaps, be received by thofe phi- 

 Jofophers w^ho admit only a certain number of 

 mechanical principles, and rejed every thing as 

 falfe which depends not upon them; and, as the 

 explication now given of nutrition and repro- 

 dudion has no connection with any of thefe 

 principles, they will conclude that it deferves 

 no credit. But I think very differently from 

 thefe philofophers. In admitting only a few 

 mechanical principles, they confider not how 

 much they contract the bounds of philofophy, 

 and how few phaenomena can, by this narrow 

 method of thinking, be fully explored. 



The notion of explaining all the appearances 

 in Nature upon the principles of mechanifm, is, 

 doubtlefs, a great exertion, and was firft attempt- 

 ed 



