JAIIUABT 20, 19in 



SCIENCE 



95 



the numbers of recent contributions wMch 

 may be cited. The positive advance im- 

 plied is so marked as to justify this dis- 

 cussion within two years of the time when 

 the entire matter was presented compre- 

 hensively in connection with the various 

 Darwin anniversary programs. 



It is unanimously agreed that organisms, 

 plants as well as animals, change individu- 

 ally in aspect, in form and structure of 

 organs, in functionation and habit as they 

 encounter swamps, saline areas, gravelly 

 uplands or slopes, climatic differences 

 identifiable with latitude or elevation, and 

 other physical and biological factors. It is 

 assumed that these somatic alterations are 

 accommodative and adaptive, making the 

 organism more suitable for the conditions 

 which produce the changes. Such an as- 

 sumption is an over-reaching one. Any 

 analysis of the changes which an organism 

 undergoes after transportation to a new 

 habitat will disclose one, or a few altera- 

 tions which might be of advantage in deal- 

 ing with the newly encountered conditions, 

 but with these are many others, direct, 

 necessitous, atrophic or hypertrophic as to 

 organs which have no relation whatever to 

 usefulness or fitness. Further, a critical 

 examination fails to disclose any theoret- 

 ical considerations or any actual facts 

 which would connect inevitably the so- 

 matic response with the nature of the ex- 

 citation, outside of the specialized tropisms 

 in which specific reactions are displayed. 

 Even in these the adjustment is of such 

 nature that a mechanism specially respon- 

 sive to contact, tendrils, for example, re- 

 sponds in the same manner to temperature 

 variations, to which the movements are in 

 no sense accommodations or adjustments. 



With regard to the more obvious and 

 direct responses of organisms to altered 

 environment, the records of the operations 

 of the horticulturist, the agriculturist and 



the breeder as to the behavior of crops, 

 plants and domestic animals, when trans- 

 ferred from one habitat to another, are 

 rich in information. The greater part of 

 such data is the result of observations 

 which do not comply with the ordinary 

 reqiairements in the avoidance of error so 

 that strict comparisons as to the behavior 

 of organisms under the conditions of 

 various habitats are impossible, but the 

 literature yields many suggestions for ex- 

 perimental research, and the simple gen- 

 eralization that the direct effects of climatic 

 complexes on the seasonal cycle, and upon 

 color, or structural features of the individ- 

 ual, may be repeated or carried over two 

 or three generations, in a habitat where the 

 specific causal combinations are lacking. 



Although organized with due regard to 

 the requirements of strict experimentation, 

 the lowland and alpine cultures of plants 

 by Nageli and Bonnier offer us nothing 

 more decisive than the above. Likewise 

 many experiments dealing with the re- 

 sponses of organisms to selected agencies 

 have obtained nothing but negative results, 

 even when artificial selection was em- 

 ployed to accentuate or perpetuate the 

 feature constituting the reaction. 



Buchanan working with Streptococcus 

 lacticus finds that phases of fluctuating 

 variations of certain features induced by 

 external exciting agencies may not be 

 fixed and are not transmissible. Jennings ' 

 cultures of paramoecia were carried 

 through hundreds of generations with no 

 progressive action in fluctuating variabil- 

 ity, while the organism, as a whole, Wcis 

 strongly resistant to all kinds of environie 

 influences : actual alterations were ex- 

 tremely rare. Most of the supposedly ac- 

 quired characters disappeared in two or 

 three generations by fission. 



In the experiments of Sumner mice reared 

 in a warm room were found to differ con- 



