NATURAL SELECTION 27 



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 and 

 J. Mark Baldwin have emphasized the importance of plas- 

 ticity, showing very clearly that the ability of the individuals 

 of a species each to so 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 selection shall 



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have time to secure the fundamental adaptation of the 

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

 viduals will be born in a condition so suitable to their sur- 

 roundings that thev will not need to chancre their structure 



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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 



