INTRODUCTORY OBSERVATIONS. XVU 



times their fize. Several naturalifts have affum=' 

 ed the fmiplicity of organization, as the means of 

 explaining different phenomena exhibited by ani- 

 mals. To me this feems mofl fallacious reafon- 

 ing. The organic flrudlure of one animal is 

 fmiple, only vi^hen compared with another known 

 animal. If it lives, it is perfeQ: in its kind. Be- 

 caufe no heart, lungs, brain, or nerves, are vifi- 

 ble, we can feldom pofitively affirm either that 

 thefe organs do not cxift, or that there are no 

 other parts which perform the functions belong- 

 ing to the mod important of them. Indeed, in 

 the fimple animals before us, they may be fo di- 

 verfified, difguifed, and incorporated or partition- 

 ed into its fubftance, as, feparately, to be invifi- 

 ble or irrecognifible, but, colledively, capable of 

 performing every vital fundion. Some may 

 have lefs neceffity for the important organs 

 which we behold in the larger animals. A muf- 

 cular heart is not equally effential to all that even 

 have one. In general they inftantly die, when 

 deprived of it ; but the life of feveral, thus muti- 

 lated, endures longer than that allotted to certain 

 animals in their mod perfed ftate. The pulfa- 

 tion of one heart will ceafe the moment that it 

 is wounded ; another will beat long after being 

 torn from the body. Some agents, deftructive 

 of life, will deftroy its irritability ; others will 

 produce no fenfible effe<^. Penetration of the 

 Vol. I. c train 



