Formerly pursued from the standpoint of the mere topo- 

 graphical relation of the parts, the conception of the 

 plant as an organism with interrelated and interdependent 

 tissues began to fall into abeyance, until a new point 

 of view has within recent times revivified a somewhat bar- 

 ren field. This point of view is the physiological one, the 

 correlation of structure and function. Here the student 

 of gross morphology and the anatomist unite in a physio- 

 logical interpretation of the form and structure of plant 

 organs, from which has grown the study of experimental 

 morphology. Advance in this direction has been consid- 

 erable, and we have now a much clearer idea of the nature 

 and development of plant organs; or at least, we have a 

 much better attitude in the interpretation of the facts 

 that have been established regarding these matters. The 

 danger which lies in this attitude is the well known one 

 of teleological reasoning, and consequently it behooves us 

 to have some caution in accepting, without thorough evi- 

 dence, the interpretations which may be made of the rela- 

 tion of form and function and of special adaptations for 

 special purposes. As some one has written, "so many 

 things may be true and so few things really are in the 

 matter of use of special organs," that we must demand 

 above all things experimental evidence before we can 

 accept as conclusively proved any statement as to function. 

 It is permissible to say without such proof that such and 

 such an explanation is plausible, but beyond that is uncer- 

 tain ground and mere assertion shows a temerity at once 

 magnificent and pitiable. On the other hand, it is ques- 

 tionable if the extreme attitude of iconoclasm as to long 

 established interpretations is necessarily a wholly reason- 

 able one. Destructive criticism is not difficult, and unless 

 some new and better interpretation is suggested the ad- 

 vance in a scientific sense is not considerable. 



A further development from this physiological attitude 

 14 



