90 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



being preferable to the more usual one " conditions " in this 

 connection, as the latter would not cover the whole field. 

 It is in quite an unpretentious and merely descriptive 

 sense that the expression " means " should be understood at 

 present ; what is usually called " conditions " is part of the 

 morphogenetic means in our sense. 



ft'. The Internal Elementary Means of Morphogenesis 



We know that all morphogenesis, typical or atypical, 

 primary or secondary, goes on by one morphogenetic 

 elementary process following the other. Now the very 

 foundation of these elementary processes themselves lies in 

 the elementary functions of the organism as far as they 

 result in the formation of stable visible products. Therefore 

 the elementary functions of the organism may properly be 

 called the internal " means " of morphogenesis. 



Secretion and migration are among such functions ; the 

 former happening by the aid of chemical change or by 

 physical separation, the latter by the aid of changes in 

 surface tension. But hardly anything more concrete has 

 been made out about these or similar points at present. 



We therefore make no claim to offer a complete system 

 of the internal elementary means of morphogenesis. We 

 shall only select from the whole a few topics of remarkable 

 morphogenetic interest, and say a few words about each. 



But, first of all, let us observe that the elementary means 

 of morphogenesis are far from being morphogenesis them- 

 selves. The word " means }: itself implies as much. It 

 would be possible to understand each of these single acts in 

 morphogenesis as well as anything, and yet to be as far 



