

PREFACE ix 



responsive peculiarities, characteristic of given tissues, from 

 their simplest types in the plant to their most complex in the 

 animal. The value of such a comparative method of study, 

 for the elucidation of biological problems in general, is 

 sufficiently obvious. Exception may be taken with regard 

 to the unorthodox point of view from which various ques- 

 tions in animal physiology have been approached. It must 

 be remembered, however, that in this work the attempt has 

 been to explain responsive phenomena in general on the 

 consideration of that fundamental molecular reaction which 

 occurs even in inorganic matter. My mode of investigation 

 has thus been determined by the necessary progression 

 from simple to complex, and by my conviction as to the 

 continuity which existed between them. And from this 

 attempt it will be seen that various results, which, accord- 

 ing to the so-called vitalistic assumption were anomalous, 

 are, in fact, capable of an increasingly simple and satis- 

 factory explanation. It must also be understood that my 

 work deals mainly with the electrical response of plants, 

 and that its extension into the field of Animal Electro- 

 physiology was intended for the demonstration of the con- 

 tinuity between the two. It was therefore impossible, in 

 the short space at my disposal, to make more than the 

 brief necessary references to the different theories already 

 in vogue concerning the response of various animal tissues. 

 These will be found, in all their detail, in the excellent 

 account given in the standard work of Biedermann. 1 



For the sake of clearness, however, I shall at this point 

 enumerate a few only of the points of difference between 

 current views and the results, obtained from actual experi- 



1 Biedermann, Electro-physiology (English translation), 1896. 



