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THE AMERICAN NATURALIST [Vol. XLVII 



such seems to be the case. That an isolated blastomere 

 representing a half or a quarter of the egg of AmpUoxus 

 should be able under favorable conditions to develop 

 into a complete larva is at first sight a surprising fact 

 and seems to give evidence of a remarkable power of 

 adaptation. But such an interpretation is far from justi- 

 fiable. The growth of the isolated blastomere seems to 

 me much more like the falling of a fainting person than 

 like a process devised to meet a special emergency, and, 

 important and illuminating as this growth is from the 

 standpoint of our understanding of the mechanism of 

 the egg, it is, I believe, a good case of pseudo-adaptation 

 rather than of true adaptiveness. All eggs certainly do 

 not show this trait and to single out the egg of Amphi- 

 oxus and extol this reaction as an adaptation is to give 

 to it weight beyond its deserts. To call this an adapta- 

 tion is to read adaptation into it as only an overzealous 

 advocate could do. Dame Nature under the circum- 

 stances might well be likened to a certain English poet, 

 who, on visiting incognito an exposition of his own 

 verses, was amazed at the wonders they were said to 

 ^contain. 



The majority of animal reactions are, in all probabil- 

 ity, neither conspicuously advantageous nor disadvanta- 

 geous to the life of the individual. They are dependent 

 chiefly on the material composition of the given organism, 

 and, so long as they are relatively indifferent to the con- 

 tinuance of life, they pass without special consequence. 

 Relatively speaking only now and then do we have condi- 

 tions where a vitally important form of response, an adap- 

 tive response, appears. On the whole the flow of action in 

 the daily life of many organisms requires little of such 

 special activity and proceeds at the level of mild indiffer- 

 ence. In other words, adaptive reactions as the controll- 

 ing factors in animal life are, I believe, by no means so 

 universal as some of their advocates would have us think. 



The world at large affords an environment in which 

 each animal has a wide range for possible reactions and 



