THE LA IV OF LIA'EA T ESS, AND ITS WORKING. 223 



appear, is capable of ultimate reduction to cells of character- 

 istic kind. Nor is this all. The cells themselves are in 

 turn composed of smaller particles, and these smaller par- 

 ticles of infinitesimally minute size may be regarded as 

 consisting in turn of the essential material of life the 

 bioplasm or protoplasm with the name of which every one 

 must be more or less familiar from the part it has played 

 in more than one grave biological controversy. But the 

 body of every living thing is in no case stable, viewed 

 either in its chemical or in its more purely physical aspects. 

 It is continually, as the inevitable result of living and 



FIG. 33. Various cells, magnified. 



being, undergoing change and alteration. Chemical action 

 is wasting its substance and dissipating its energy with pro- 

 digal hand on the one side, and rebuilding and reconstruct- 

 ing its parts on the other. Its material particles are 

 continually being wasted and excreted, whilst new particles 

 are as incessantly being added to its frame. A never-ending 

 action of waste and repair is maintained within every living 

 being ; and it is not the least striking thought which may 

 ensue from the study of such a subject, that, notwithstanding 

 the constant renewal of our frames, we continue to preserve 

 the same recognisable form and features. The development 

 of new particles in place of the old appears to follow the 

 same course as that whereby the first-formed particles were 

 .guided to their place in the developing young. Germs, 



