DYXAMICS IX EVOLUTION. 69 



In the very simplest unicellular organisms we have also 

 unicellular molecular mechanisms of a most peculiar kind. 

 The fearfully complex molecular structure of these mechan- 

 isms conditions their actions, their forms and powers, no less 

 than does the nature of the watery media, in which these first- 

 lings of life, as w.^11 as the germs of higher organisms, must 

 in common develop. In the belief that the study of the 

 "living" mechanism of some of the lowest types of organized 

 existence, in relation to and as affected by their not-living sur- 

 roundings, might throw some light upon the origin of their 

 forms, the writer has here, in the main, taken up the problems 

 thus raised as physical ones. In the belief, also, that these 

 studies have not been entirely fruitless, the following evidence 

 is offered. 



An Aniccba protcus may be compared to a smoke- or vortex- 

 ring of particles that has been greatly modified, owing to the 

 very complex interaction of disturbances of the surface-tension 

 of its outer enveloping film of molecules, the viscosity of its 

 own plasma, its gravity and power of adhesion to other bodies. 

 If we conceive a smoke-ring to have become a viscous semi- 

 fluid body with an outer film of molecules, and that this ring 

 has contracted until the central opening in it has completely 

 closed, we shall have a mechanism which may be compared in 

 detail with an Amoeba in motion, provided only that we modify 

 it still further and in such ways as we are obliged to suppose 

 that the combination of the four forces above specified cooper- 

 ate in order to produce and maintain the form of an amoeboid 

 organism. Verworn ^ has already referred to the flux of the 

 particles of the Amoeba through itself, in discussing the 

 general subject of contraction, but as he has not understood 

 the complexity of the process, we need not here concern 

 ourselves further than to say that he has failed to correctly 

 interpret this vortical flux of amoeboid organisms. There 

 is, however, such a central flux of particles through the centre 

 of the body of an amoeboid, as any one can soon convince 

 himself by carefully observing the behavior of a large living 

 proteus animalcule. The chemical transformations that go on 



1 Bewegung der lebendigen Suljstanz. Jena, 1S92. 



