46 THE MYSTERY OF LIFE. 



cast upon the seashore, is due to changes 

 effected during the life of a living animal. 



The action of such tissues as nerve and 

 muscle is determined by their structure and 

 composition, which are a direct consequence of 

 the influence of vital power upon the particles 

 of matter of which they consist. We cannot, 

 therefore, show even that the action of these 

 tissues is due to physical and chemical changes 

 only, for not only is the action dependent upon 

 the structure, but the maintenance of the struc- 

 ture in a state fit for action is effected by the 

 living matter, or bioplasm, which exists in 

 greater or less proportion, and is more or less 

 active during every moment throughout life. 



But if any advocate of the physical doctrine 

 thinks I have unfairly selected a highly complex 

 structure for the express purpose of bringing 

 out too strongly the objections to his favourite 

 hypothesis, let him select some simpler tissue, 

 and explain if he can its formation according 

 to his own views. Nay, if it be preferred, let 

 the phenomena of the simplest living organism 

 in existence be taken as the subject for dis- 

 cussion. It seems to me clear that facts 

 are more favourable to the vital than to the 



