66 THE BIOLOGY OF DAILY LIFE. 



First let us understand precisely what protoplasm 

 means. We are doubtless familiar with its general 

 outline, as it looms large over the whole field of bio- 

 logical thought, but may not be quite sure of all its fea- 

 tures, as it issues from the hands of its makers. 



I may say that the word " Protoplasm" was first 

 invented by Hugo von Mohl, but I think at least all 

 English-speaking people will agree that to Professor 

 Thomas Huxley belongs the credit of making the 

 protoplasm theory more than a mere "working 

 hypothesis." He has at all events popularized, if he 



sufficient explanation of everything that cannot be explained 

 otherwise, and accordingly to defer the consideration of the 

 functions which have no demonstrable connexion with structure t 

 as for the present beyond the scope of investigation ; the other 

 is, retaining our hold of the fundamental principle of correlation, 

 to take the problem in reverse i.e., to use analysis of function 

 as a guide to the ultra-microscopical analysis of structure. I 

 need scarcely say that of these two courses the first is wrong, the 

 second right ; for in following it we still hold to the fundamental 

 principle that living material acts by virtue of its structure, 

 provided that we allow the term structure to be used in a sense 

 which carries it beyond the limits of anatomical investigation 

 i.e., beyond the knowledge which can be attained either by the 

 scalpel or the microscope. We thus proceed from function to 

 structure, instead of the other way. In thus changing direction 

 we are not departing from the traditions of our science." 



I cannot pretend to define the term " structure" in this tran- 

 scendental sense, which carries it beyond the limits of anatomical 

 or microscopic investigation. It presents itself to me as a sort 

 of castle in the air. But the last sentence I can fully under- 

 stand, from my recollections of a circus. If one is walking in 

 a straightforward course, of course to right-about-face is to 

 turn your back upon all you were once aiming at, but not so when 

 your course is circular a man who argues in a circle can reverse 

 his procedure without departing from his traditions. He argues 

 in that very circle still. 



