p8 DIGESTION, SECRETION, &c. SECT. XXXVII. 3. 



kind of gland is thus endued with its peculiar ap- 

 petency, and felects the material agreeable to its 

 tafte from the blood, but every individual pore ac- 

 quires by animal fele&ion the material, which it 

 wants ; and thus putrition feems to be performed in 

 a manner To fimilar tbfecretion, that they only dif- 

 fer in the one retaining, and the other parting again 

 with the particles, which they have {elected from 

 the blood. 



This way of accounting for nutrition from fti- 

 mulus, and the confequent animal feledtion of par- 

 ticles, is much more analogous to other phenomena 

 of the animal microcofm, than by having recourfe 

 to the mierofcopic ariimalcula, or organic particle? 

 of Buffon andNeedham ; which being already com- 

 pounded muft themfelves require nutritive particles 

 to continue their own exiftence. ' And muft be 

 liable to undergo a change by our digeftive or fe- 

 cretory organs ; otherwife mankind would foon re- 

 femble by their theory the animals, which they 

 feed upon. He, who is nourifhed by beef or ve- 

 nifon, would in time become horned ; and he, who 

 feeds on pork or bacon, would gain a nofe proper 

 for rooting into the earth, as well as for the percep- 

 tion of odours, 



The whole animal fyftem may be confidered as 

 confiding of the extremities of the nerves, or as 

 having been produced from them ; if we except 

 perhaps the medullary part of the brain redding in 

 the head and fpine, and in the trunks of jhe nerves. 

 Thefe extremities of the nerves are either of thofe 

 of locomotion, which aVe termed mufcular fibres; 

 or of thofe of fenfation, which confti tut e the im- 

 inediate organs of fenfe, and which have alfo their 

 peculiar motions. Now as the fibres, which con- 

 ftitute the bones and membranes, poflefs originally 

 fenfation and motion ; and are liable again to pof- 

 fefs them, when tliey become inflamed ; it follows, 



that 



