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THE AMERICAN NATURALIST [Vol. XLV 



considered as capable of adaptive alterations to every new 

 agency which may cause changes in its form, structure 

 or functionation. 



Next we come to the very crux of the whole matter : do 

 the unusual forms or activities of organs resulting from 

 environic causes act in any manner upon the germ-plasm 

 connected with such altered bodies? If we are to con- 

 sider the activities of the organism or of the cell to de- 

 pend mainly upon its chemical structure and constituency 

 and such a generalization seems unavoidable, then we 

 have means by which the soma might cause its proper- 

 ties to be reflected from the germ-plasm in a succeeding 

 generation, since the chemical mechanism of the soma 

 and germ-plasm must be of the most intimate nature. 

 That some such connection does actually exist is strongly 

 suggested by the behavior of a great number of organ- 

 isms which have been seen to carry marked environic 

 effects to the second or even third generations; if the 

 interrogation he made as to why the induced qualities are 

 carried no further it may be said that the reply may be 

 suggested by the results of long-continued action of the 

 exciting agency, such as lias been used by AVoltereck with . 

 Daphnia. 



If a general view be taken of the available information 

 of interest in this connection, three classes of facts will 

 be discerned. One group is comprised in the mass of in- 

 formation obtained by the operations of the horticul- 

 turist, the agriculturist and the breeder as to the behav- 

 ior of crops, plants and domestic animals, when trans- 

 ferred from one habitat to another. The greater part of 

 such data is the result of observations which do not com- 

 ply with the ordinary requirements in the avoidance of 

 error so that strict comparisons as to the behavior of 

 organisms under conditions of various habitats are im- 

 possible. A consideration of the literature yields many 

 suggestions for experimental research and the simple 

 generalization that the direct effects of climatic com- 

 plexes on the seasonal cycle, and upon color, or struc- 



