SCIENCE AND PHILOSOPHY OF THE ORGANISM 



shows us that it actually has raised all of them. All 

 movements, in some way, are reactions to external stimuli, 

 i.e. are changes of the organic body in question with regard 

 to its external surroundings. In other words, there is a 

 line of processes, the first of which leads from without to 

 within, whilst the last one leads from within to without ; 

 and besides these there are intermediate processes. We 

 now may ask : What happens in the organism when it 

 receives the external stimuli, what is the final effect of 

 these stimuli, and what is there between the stimulus and 

 the final effect ? 



The physiology of the so-called sense organs would give 

 us the answer to our first question ; it would teach us to 

 what sorts of stimuli the organisms are responsive and by 

 what means of their organisation and function they are so. 

 The physiology of locomotory organs takes account of the 

 question about the final acts in the process of movement : 

 the contraction of the muscle is studied, but so is also the 

 ciliary movement in infusoria, or the strange process of 

 secretion and absorption of gases by which the movements 

 of Siphonophora or of Eadiolaria are carried out. 1 And all 

 intermediate processes concerned in organic movements 

 would come under the physiology of the nerves and nerve- 

 centres. Not very much is actually known about this 

 subject. Scarcely anything has been ascertained with 

 regard to the so-called "centres"; and as to the nerves 

 themselves we know little except that nervous conduction 



1 Rhumbler shares the merit of having studied very extensively the means 

 of movement in the lowest Protista. Even if he is wrong in many points 

 of his interpretation (Jennings, Heidenhain) he has done good work in 

 clearing the problems. But I beg to lay stress upon the fact that he only 

 has studied means of movement nothing more. 



