188 Cai'ses and Course of Organic Evolution 



body — inorganic and organic alike — then all nature is a lusiis 

 naturae, a gigantic scientific deceit. If, on the other hand, 

 extremely complex molecules, that are unquestionably ener- 

 gized — as every chemist of the colloid groups acknowledges — 

 by extremely condensed amounts of energ>% possess a mobility 

 and yet stability such as Graham emphasized for all colloids; 

 and if these, like all inorganic compounds and many crystalline 

 products of organic bodies, are influenced by environment 

 so as to pass even from the crystalloid to the colloid state, from 

 the condition of sugar to that of starch, and so on, then surely 

 environment acts on all organic bodies, if these show, in every 

 detail of evolutionary progress, peculiarities that become in- 

 creasingly explicable as we the more fully and precisely use 

 the environal key to explain the often tangled details. The 

 beautiful studies of Ryder on strain distribution and digit 

 modification in mammals (JJ: 607), and those of Cope on 

 mammalian dentition, can only be interpreted as progressive 

 modification through reaction to the action of mechanical 

 or molic stimuli. 



If now a definition for environment be sought for in current 

 dictionaries, that from the "Century" is long, and owes its 

 value more from its explanatory fullness than its epigram- 

 matic neatness. "The sum of the agencies and influences 

 which affect an organism from without; the totality of the 

 intrinsic conditioning to which an organism is subjected, as 

 opposed to its otvti intrinsic forces and therefore as modifying 

 its inherent tendencies, and as a factor in determining the 

 final result of organization. It is an expression 'used' in ex- 

 plaining that at a given moment a given organism is the result- 

 ant of both intrinsic and extrinsic forces, the latter being its 

 conditions of environment, and the former its inherited condi- 

 tions'' 



The above definition is admirable for organic structure, 

 ])ut would be practically perfect for the inorganic as well, 

 were the words "a body" to be substituted for "an organism." 

 For with our knowledge now of intrinsic atomic and molecular 

 energy, of colloidal molecules and their degree of organization. 



