38 



ties and arrangements. The flesh of animals 

 and that of fish are different in quality; 

 the mucilaginous bladders which float in 

 the sea differ from vegetables; yet all 

 are irritable, or possess this power of oc- 

 casional contraction. Though in general 

 we find irritability connected with a 

 fibrous structure, yet, if we may trust 

 our senses, it is not so in every instance. 

 In the hydatid, where no such structure 

 is apparent even with the aid of lenses, 

 we still have evidence of the irritability 

 of life. If also, as I strongly suspect, the 

 muscular fibres be not continued from 

 one end of the muscle to the other, irri- 

 tability could not in that case be consi- 

 dered as a property belonging to them, 

 since any, breach of continuity would com- 

 pletely frustrate the contraction of the 

 whole muscle. 



Thirdly, I proceed to enquire into Mr. 



