DEVELOPMENTAL MECHANICS. 153 



may be identical with those which underlie inorganic or physico- 

 chemical processes. 



Since it is not the task of the biologist, as such, to investi- 

 gate and to subject the components of inorganic phenomena to 

 an analysis further than that undertaken by physicists and 

 chemists, we may accept these components as given, and may 

 designate them, so far as they are concerned in organic opera- 

 tions, as "SIMPLE COMPONENTS," no matter how problematic 

 their nature may be, and even if sooner or later they should be 

 still further dissociated by physicists and chemists. When 

 this is accomplished, we shall make use of these further, still 

 simpler components. 



Besides the endeavor to ascertain such " simple components," 

 the lines of research in developmental mechanics must from 

 the start be guided by the conviction that organic structure is 

 mainly due to the operation of components which at present are 

 so complicated as to exceed the limits of our observation. For 

 these I have suggested the term " COMPLEX COMPONENTS " (2). 

 Although according to our immediate conception of the matter, 

 even these components depend in the last instance on inorganic 

 modi operandi, nevertheless the complexity of their composition 

 lends them attributes which often differ so widely from those of 

 inorganic modi operandi that they are not only very dissimilar 

 but even appear to contradict in part the functions of these 

 same inorganic modi operandi. This is the case with the non- 

 exosmosis of salts from living fish-eggs in water, the non-desic- 

 cation of small living insects in the sunlight ; whereas after 

 death, these organisms, in the former instance suffer diosmosis, 

 in the latter desiccation ; another instance is the pouring of a 

 glandular secretion into a cavity which is under higher pressure 

 than that which obtains in the blood capillaries of the gland. 

 These processes show that in the former instances the salt or 

 the water is not in a free state, but fixed and operant 

 (beschaftigt), whereas in the last instance we are dealing with 

 specific active functions carried out with commensurate expense 

 of energy on the part of the epithelial cells. 



It must, therefore, be our next most important task to ascer- 

 tain these components, which, though complex, arc nevertheless 



