PROBLEMS OF MODERN SCIENCE 



is undoubtedly one of the most promising lines of 

 future research in connection with genetics and the 

 problems of evolution. Those who attempt ex- 

 planations of heredity, variation, and development 

 which disregard or are contrary to the known 

 facts of cell-structure are likely to find them- 

 selves following blind trails which lead nowhere. 

 Genetics has become the most active and many- 

 sided recent movement in botany, or even in 

 biology at large, and its future development will 

 represent the synthesis of results obtained from 

 many independent lines of research. 



In the immediate future much attention will 

 no doubt be devoted to the appraisement of the 

 relative values to be attached to different evolu- 

 tionary factors, such as natural selection, mutation, 

 orthogenesis, and the neo-Lamarckian factor. The 

 latter is now again receiving serious attention, and 

 seems destined to form the basis of explanation of 

 many cases of adaptation, particularly those in 

 which recapitulation is involved in the develop- 

 ment of the organism. If these results are to 

 represent steady progress they must be based not 

 upon speculation, but upon an experimental 

 analysis of the incidence and action of the various 

 factors involved, and their relationship to each other 

 in bringing about that panorama of events which 

 we call organic evolution. 



R. RUGGLES GATES 

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