THE NEW CELL DOCTRINE 13 



Homogeneous protoplasm is of the greatest rarity and as yet 

 has been studied chiefly by the American, E. B. Wilson.^ 

 It claims our highest interest because it represents apparently 

 the simplest condition of the living substance which we 

 know. In the second state we find the protoplasm consists 

 of two flviids which exhibit a foam structure, that is to say, 

 the two fluids are so mixed together that one, apparently 

 the more fluid, forms droplets and the other holds these 

 droplets apart and separates them from one another com- 

 pletely. As is well known. Professor Butschli has specially 

 studied protoplasm in this condition, and has founded the 

 theory, which he has further defended, that we encounter in 



Fig. 9. — Striated muscle fibers of a rabbit, colored by Bielschowski's method 

 and then teased so as to demonstrate the single muscle fibrillse. — After a preparation 

 0} Prof. Poll's. 



this foam structure the essential true fundamental structure 

 of living substance. For this view much may be said. 

 Whether, however, we may assume that protoplasm, which 

 is apparently homogeneous, also really possesses a foam 

 structure, although it escapes our present observation, must 

 remain undecided. In its third condition protoplasm is no 

 longer simple because new structures have arisen in it which 

 are probably also hving, but which differ from protoplasm 



