PHYSIOLOGY OF THE INVERTEBRATA. 19 



From what has been said in this chapter it will be gathered 

 that " a mass of living protoplasm is simply a molecular 

 machine of great complexity ; but it must not be supposed 

 that the differences between living and not-living matter are 

 such as to bear out the assumption that the forces at work in 

 the one are different from those which are to be met with in 

 the other. Considered apart from the phenomena of con- 

 sciousness," Professor Huxley says, " the phenomena of life 

 are all dependent upon the working of the same physical and 

 chemical forces as those which are active in the rest of the 

 world." 



