THE ACTIVE FORCES OF LIVING ORGANISMS 77 



would exist. Chemical action once started would 

 cause, as is always the case, diffusion in the substance 

 rendered active, and the entrance of the particle in 

 the area adjacent to it would thus be provided for, 

 or at least facilitated. The chemical action would, 

 it may be supposed, cause some sort of vibration. 

 Whether this would be molecular or electrical we 

 cannot very well determine, though it seems natural 

 to suppose that as in the case of the nervous impulse 

 it would be of a compound nature. In any case, we 

 may speak of it in a general way as an oxidation 

 wave, and we may assume that it would cause in the 

 nucleus also a slight amount of oxidation. These 

 events constitute what one may term the chemico- 

 sensory factors in absorption. Though more com- 

 plicated they are of the same order in the higher 

 animals. Hydrification and oxidation in one form or 

 another are the chief processes. Chemical action, 

 chemico-sensory impulses accompanied by diffusion or 

 loosening of the surface in contact with the food — 

 these are the common factors in absorption in high 

 and low organisms, and to these must be added 

 another, viz., motion, which may be recognised by 

 the presence of muscular fibres in the mucous 

 membrane of the intestines as it may in the thrusting 

 out of the pseudopodia of the amoeba. The exact 

 nature of the latter event is, however, wrapped in 

 considerable obscurity, although it seems to depend 

 on certain events taking place in the substance of the 

 amoeba and in the nucleus. 



