CONDUCTIVITY 153 



represents a mixture of colloid substances and actual solutions. 

 Frequently, if not always, living structure presents a morpho- 

 logical differentiation of two types, when seen under the micro- 

 scope, in the form of a foam structure described by Biitschli. 

 (Figures 27 and 28.) If we suppose that with the disintegra- 

 tion of complex molecules, which we must assume as taking place 

 in the material of the walls of the protoplasm network, sub- 

 stances are formed which are subjected to electrolytic dissociation, 

 the anions and kations hereby liberated must be diffused from 

 the place of their separation into the surroundings. Their dif- 

 fusion, however, is restricted by the protoplasmic network. The 

 positive ions may pass through, but the negative ions may not. 

 As a result : the reticulated substance is the seat of electric dis- 

 charge, which in turn gives the impact to the breaking down of 

 new molecules and with this to the occurrence of new potential 

 differences, and so on, consequently the disintegration is extended 

 further and further through the connected masses of the proto- 

 plasmic framework. 



This theory, founded on facts gained entirely from investiga- 

 tion, would involve those forms of energy which play the role of 

 activator in the extension of the breaking down of the molecule 

 from cross section to cross section, namely, the osmotic and the 

 electrical energy. Based on the general properties of physical 

 chemistry and those of morphology of the living substances, they 

 would be applicable to all vital systems. It would be premature 

 to attempt to extend this assumption and further develop its 

 specific details, above all to make it responsible for the specific 

 differences in the process of the conduction of excitation in 

 various forms of living substance. For this our knowledge of 

 the properties of living substance is still far too incomplete. 

 Nevertheless, it furnishes us even now with various points of 

 view for the further analysis of a series of vital manifestations, 

 as, for instance, the facts concerning the production of electricity, 

 of galvanotaxis, chemotaxis and so on. This, however, exceeds 

 the limits of the task we have here mapped out. We are con- 

 cerned here solely with the general principle on which the con- 

 ductivity of excitation in the living substance is founded. 



