Xo. 4<J6] ASPECTS OF THE SPECIES QUESTION 281 



locality. The herbarium then becomes a record of his 

 field observations. Much good work can be done in the 

 herbarium, but when coordinated by abundant observa- 

 tions upon the plants, as they occur in nature, the conclu- 

 sions are much more likely to be correct. 



Mr. G. H. Shull: I would like to say one word in re- 

 ply to Mr. Hitchcock's remarks regarding what we know 

 about variations when we seen them in the field. It is 

 my experience in the cultivation of things brought in 

 from the field during the last four years, that we know 

 nothing about the significance of variations in the field 

 as to their bearing upon the question of the species, if 

 by species we mean a continuously variable group, be- 

 cause in some instances we find that very distinct varia- 

 tions as seen in the field are immediately lost when the 

 individuals possessing them are grown under uniform 

 conditions. We find, on the other hand, that equally dis- 

 tinct, or even less distinct variations— as determined en- 

 tirely by an estimate of the difference in form— are re- 

 tained with absolute permanence so far as one can 

 determine by three or four years of culture under like 

 conditions. Now, how we can tell without an experi- 

 mental basis for the estimation of the meaning of varia- 

 tion in any particular species, what is the significance 

 of those variations as we see them in the field, I am at a 

 loss to understand. 



