46 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



though in a smaller form ; there is no " evolutio " in the old 

 meaning of the word. 



The word "evolution" in English usually serves to denote 

 the theory of descent, that is of a real relationship of all 

 organisms. Of course we are not thinking here of this 

 modern and specifically English meaning of the Latin word 

 evolutio. In its ancient sense it means to a certain degree 

 just the opposite ; it says that there is no formation of any- 

 thing new, no transformation, but simply growth, and this is 

 promoted not for the race but for the individual. Keeping 

 well in mind these historical differences in the meaning of 

 the word " evolutio," no mistakes, it seems to me, can occur 

 from its use. We now shall try to obtain a few more 

 particular results from our descriptive study of morpho- 

 genesis, which are nevertheless of a general bearing, being 

 real characteristics of organic individual development, and 

 which, though not calculated of themselves to further the 

 problem, will in any case serve to prepare for a more 

 profound study of it. 



The totality of the line of morphogenetic facts can easily 

 be resolved into a great number of distinct processes. We 

 propose to call these " elementary morphogenetic processes "; 

 the turning in of the endoderm and its division into three 

 typical parts are examples of them. If we give the name 

 " elementary organs " to the distinct parts of every stage of 

 ontogeny which are uniform in themselves and are each 

 the, result of one elementary process in our sense, we are 

 entitled to say that each embryological stage consists of a 

 certain number of elementary organs. The mesenchyme ring, 

 the coelum, the middle-intestine, are instances of such organs. 

 It is important to notice well that the word elementary is 



