NATURAL SELECTION 2? 



their surroundings. Under changing environmental con- 

 ditions, especially if the changes be rapid and considerable, 

 the more plastic species, and those in which the largest 

 degree of variation is present, will have a decided advantage 

 over their less readily modified neighbors, and those species 

 which do not so greatly vary. Many of the less plastic and 

 less variable species may be destroyed because of their in- 

 ability to keep pace with the changes in their surroundings. 

 The plasticity of the organism and its variation are, there- 

 fore, important elements, and the degree to which they are 

 developed in any given species may have an important 

 bearing upon the fate of that species. Lloyd Morgan, J. 

 Mark Baldwin, and H. F. Osborn have emphasized the im- 

 portance of plasticity, showing very clearly that the ability 

 of the individuals of a species each so to change its habit or 

 structure as to adapt itself to new disadvantageous conditions 

 may preserve its life and so prevent the rapid extermination 

 of the species when environmental conditions change for the 

 worse. In this way a plastic species may be tided over a 

 period of hurtful environmental changes until natural selec- 

 tion shall have time to secure the fundamental adaptation 

 of the species to its new conditions of life, after which the 

 individuals will be born in a condition so suitable to their 

 surroundings that they will not need to change their struc- 

 ture or natural habits in order to survive. In a species which 

 withstands unfavorable environmental conditions through 

 the plasticity of its individual members, each individual will 

 need to be educated into harmony with the environment. 

 Such individuals of the species as vary toward greater 

 natural adaptation will need less education. Of course 

 innate adaptation is more advantageous than adaptation 



