10 BULLETIN OF THE NATURAL HISTORY SOCIETY. 



The other great j)re-reqnisite is a proper training in 

 the three scientific faculties — observation, experiment, 

 judgment. 



"We have ah-eady but just referred to field study, 

 and the local botanist's opportunities for it. It cannot be 

 emphasized too often, nor too strongly, that just here is 

 his true field, and that his greatest triumphs will come 

 from his observation of nature in action. It is under 

 the extreme conditions of nature that her adaptations 

 are best seen, and in all seasons and times and weathers 

 the observer should be abroad, alert, persistent, sympa- 

 thetic. The effects of storms on the branches, of rain 

 on the flowers, of heat on the leaves, of birds on the 

 fruits, of innumerable other external agencies, can be 

 learned only by seeing them in operation, and the}" 

 make clear the responsive adaptations in i)lants. The 

 observer, indeed, is greatly aided by this dual nature of 

 his problems, — the operations of agencies upon the plant, 

 and the adaptations in the plant to the agencies ; either 

 may form a guide in the search for the other. The field 

 observer can settle what the indoor worker can but guess 

 at, and make discoveries of which the latter would never 

 dream. But the more concrete treatment of this most 

 important matter belongs under the special sections to 

 follow. 



The great adjunct of observation is apt experiment, 

 and for Phytobiology this of the simplest and most direct 

 sort. The mere cutting away of a branch, the isolation 

 of a flower by a muslin cover, the pinning of a leaf 

 to a fixed position are types of simplicity of experiment 

 which, when tried in test of a definite question, 

 have made clear some of the deepest principles. By 

 what simple methods great truths can be laid bare is 

 illustrated by Darwin's phytobiological work, particularly 



