LIVING PRINCIPLE. 115 



construction of the two animals is exactly the same, and therefore de- 

 pends upon some peculiarity in the ' Principle of Life.' 



Living Principle illustrated by the mutual attraction of Parts for 



union. 



How do parts of a living hody grow into one another ? I should 

 suppose that this is entirely owing to the simple Living Principle ; 

 that whenever two parts which have an affinity — which are sensible of 

 one another — come into contact, and the impression each receives is the 

 same, the effect on both must be the same, and the desires from such 

 sensations the same, like a kiss. The result of which is, that they 

 come into mutual apposition, vessel to vessel, and the two become one 

 substance ; all similarities on each side attaching themselves together. 



The Living Principle appears to be the same 1 in all animals ; for 

 whenever two parts of the same animal, or two parts of different ani- 

 mals, come into contact, they unite into one ; and if both have con- 

 nexion with the heart or hearts, each part is in some measure supplied 

 as before ; only, that each part is capable of supplying its neighbour. 

 But if either part be deprived of its heart, either before or after its 

 union, that part is immediately supported by the other, and its Living 

 Principle is supported ; but nothing more is done ; for, whatever dis- 

 position either or both had, they still retain that disposition and acquire 

 none of the other. For instance, a spur of a cock still continues to 

 grow a spur when transplanted to the comb. Nor does the stock on 

 which a sucker of a tree is inserted seem to be altered in its disposition. 

 Each with regard to disposition seems to be a perfect Being, with one 

 Living Principle. 



Of Simple Life. 



We find this principle called ' Simple Life ' much more in some animals 

 than others. This difference is not confined to peculiar classes of animals 

 entirely, although it is so in some degree. I believe it is pretty equal 

 in all the Teiracoilia. Few, if any, live long after being deprived of 

 the action of respiration, or of communication with the brain ; life, 

 indeed, is then of but very short duration. However, as none of this 

 class are uniformly constructed throughout, there being some parts 

 which have a greater dependence upon their connexion with the first 

 principles [of life] than others, we find that ' Simple Life ' is of much 

 shorter duration in those parts than in those which have not this con- 



1 [The same in essence, not in degree] is here meant. 



l2 



