MILES ON FUTILE EXPERIMENTS IN AGRICULTURE. 37 



mental methods of research, and they must largely depend upon the 

 critical observation of phenomena as they occur for their progressive 

 development. 



In nearly all of the problems requiring investigation in agriculture 

 biological activities are the dominant factors concerned in the reactions 

 of matter and transformations of energy, and the complexity of the con- 

 ditions presented is intensified by the involved interdependent relations 

 of the biological, physical and chemical factors that cannot be separately 

 investigated. 



Our knowledge of the life history and habits of organisms, and the 

 development, morphological relations, and functions of mere organs of 

 nutrition and reproduction has been derived almost exclusively from 

 the observation of the various forms of life under normal conditions, 

 and there is an obvious limit to the application of exact experimental 

 methods from the interference of the required artificial conditions with 

 the normal activities of the organisms that are the subject of inquiry. 



The heredity of acquired characters is generally accepted as a funda- 

 mental principle in the improvement of domestic animals, and culture 

 and heredity are looked upon as the essential factors in the improvement 

 of the pure breeds. 



On theoretical grounds the followers of Weissman claim that acquired 

 characters are not inherited and it is proposed to test the truth of their 

 assumptions by an appeal to direct experiments. There are however 

 insuperable difficulties in the way of the application of this method. 

 There are many diverse characters inherited by each individual, and the 

 frequently observed facts of atavism indicate that no limit can be as- 

 signed to the inheritance of ancestral characters. 



There is a decided preponderance of evidence in favor of the view that 

 all characters of all ancestors are inherited, and that the dominant or 

 obvious characters may obscure less pronounced characters that may 

 remain latent for many generations until favorable conditions of habit 

 or environment bring them to the surface as dominant characters. 



In the inheritance of an acquired character it is obvious that modified 

 tunctional activities must precede morphological changes, and this ex- 

 plains why the results of accidents are not inherited. 



The incipient indications of the inheritance of an acquired character 

 must be manifest in functional changes of the organism that are not 

 as readily observed as morphological changes. An acquired character 

 might be inherited and transmitted for several generations without be- 

 ing noticed, as it would at first in all probability be obscured by the 

 dominance of some well established ancestral characters. The history 

 of the improved breeds and the observation of breeders furnish better 

 evidence in regard to the laws of heredity than can be obtained by direct 

 experiment. 



Similar difficulties arise in field and feeding experiments, so far as 

 the discovery of principles that can be profitably applied in practice are 

 concerned. The conditions presented are too complex to permit of the 

 isolation of the various factors involved to determine their real signifi- 

 cance as required in exact methods of research. 



Experiments to determine the relative nutritive value of foods are 

 fallacious from the number of variable factors involved in the problem 



