No. 509] 



ECOLOGY OF INDIAN CORN PLANT 



21)'.) 



young is a case of maladaptation, since the plant has 

 least to offer when it is most heavily drawn upon. It 

 will be noticed, however, that this early spring- attack is 

 mainly delivered by insects which come into corn from 

 some other vegetation, chiefly from grass, and whose oc- 

 currence in the corn field is scarcely more than accident;)!. 

 The motive to an adjustment of habits and life histories to 

 the capacities of the plant is therefore virtually wanting, 

 and seems at any rate impossible, owing to the variability 

 and inconstancy of the several factors involved. 



Conclusion 



From the foregoing it will be seen that the corn plant 

 is not only an exotic in its origin, but that, aside from its 

 relation to man, it still remains an unnaturalized for- 

 eigner, not sufficiently adapted to our conditions to sur- 

 vive without the constant supervision of a guardian and 

 the services of a nurse. The corn field contains an arti- 

 ficial ''association" persistently maintained by human 

 agency in the midst of a hostile environment, to which it 

 would promptly succumb if left to itself, and as such it 

 would seem to offer to the ecologist all the advantages of a 

 vast and long-continued experiment, by a study of whose 

 results he may learn something of the maimer in which 

 ecological relations may be affected when a plant takes 

 advantage of a single favoring condition to push its way 

 into a territory foreign to its former habits. 



This corn plant, at least, which has certainly lived in 

 our territory under the care of man for several centuries, 

 and perhaps for some millenniums, has even yet no 

 specialized friends active in its service, and no struc- 

 turally adapted enemies enlisted against it, such special- 

 izations of injurious relationship as one detects being 

 clearly due to other than structural differentiations. 

 During all this long period, it has been widely and 

 steadily forced into a strange ecological system which has 

 nevertheless scarcely yielded to it at any point. It has 

 produced, it is true, by its enormous multiplication and 



