194 ECOLOGY 



their seeds, or the highly complex adaptations of their flowers to se- 

 cure cross-pollination. What facts of systematic botany, for instance, 

 can be compared in popular interest with the adaptations of the ant- 

 plants or the marvelous biological relations of the Yucca flower and 

 Pronuba moth so critically studied by a distinguished botanist of 

 this city? Ecology presents plants in their most human aspect. It 

 deals with their struggles for room, light, and food. 



It would be natural to suppose that a subject so varied and fascin- 

 ating would have been among the earliest phases of plant study to 

 receive attention, but it is only within the last two decades that 

 ecology has asserted itself as a department of botany. Of course, 

 the observations and records upon which ecology rests have been 

 accumulating for centuries. The task which has been accomplished 

 in recent years is the arrangement of these observations in new se- 

 quences and their interpretation from a new point of view. It is 

 scarcely necessary to say that the new standpoint was furnished by 

 the theory of evolution. 



This being true, however, it would be natural to ask why the effect 

 was not more immediate, and why a quarter of a century elapsed 

 between the clear enunciation of the Darwinian hypothesis arid the 

 first organized study of ecology. This was due chiefly to two causes. 

 In the first place the Darwinian theory itself was, in its varied aspects, 

 a matter so important, and so violently discussed in its early years, as 

 to leave among speculative biologists little attention for other mat- 

 ters. On the other hand, mechanical improvements in the micro- 

 scope, microtome, and other such apparatus had just then opened 

 great vistas of technical research along the lines of plant anatomy and 

 physiology, which consequently formed in the sixties, seventies, and 

 eighties the most popular fields of botanical study. Here the spirit of 

 investigation was by no means speculative. Anatomical structures 

 were studied in great detail, but there was an almost morbid reluct- 

 ance to theorize upon their physiological significance. In like manner 

 the physiologist was measuring and weighing, timing and recording 

 the vital processes of the plant, but his work was chiefly in the labor- 

 atory, and he was not given to speculating upon adaptations to en- 

 vironment or the complex influences which determine plant distribu- 

 tion. The plant physiology of the seventies w r as as far removed from 

 ecology as human physiology is from sociology. 



In the late eighties and early nineties a feeling arose almost simul- 

 taneously in several quarters that anatomy to be of real value should 

 be physiologically interpreted, and that physiology should go forth 

 from its laboratory to observe and name a host of processes and 

 forces of nature, which are no less important because in many in- 

 stances they can neither be measured nor weighed. The new science, 

 thus called into existence, was first spoken of as biology of plants, 



