

254 



MISSOURI BOTANICAL GARDEN 





data, and writers who may speak with the greatest authority 

 have repeatedly insisted that biogeographical researches are 

 of the greatest value only when prosecuted by those who 

 are deeply versed in the morphology and taxonomy of the 

 forms treated. When the problem is one of physiological 

 plant geography, and we have for consideration the addi- 

 tional factor of the environmental conditions and adapta- 



| 



tions thereto, the problem becomes more complex. Upon 



phological and ecological data of the problem I 

 have hardly touched in the present paper. I have sought, 

 however, to carry out my comparisons with the greatest 



in or 



I 



m 



••■- 



eral laws and transgressions of the categories recognized 

 would convince others of the validity of the propositions 



offered in this paper. 



A point which will doubtless occur to all who examine 

 into this phase of biology is that in the present work I 

 have compared the morphology and geographical distribu- 



tion of a single type of adaptation to a given facto 

 believing that the Solanum-Cassia and Melastomataccous 





types may be ( 

 of the Apidae, 



to the peculiar habits 

 with the form and distribution of all floral 

 types, whether representing adaptations or not. For a 

 final solution of the problem this method is obviously in- 

 adequate. It seems at first that the comparison should be 

 confined to the entomophilous forms and that these should 

 be sea-related into their various types of adaptation for 



er ~» 



comparison; but the relation of all floral structures is one 

 of such complexity that it seems that even this limitation 

 of the field may be too narrowly drawn. Concurrence in 

 both fauna and flora is here doubtless a factor of great im- 

 portance, and far-reaching structural and field investigations 

 must be made before the real relations will be finally made 

 clear. In justification of the course which has been fol- 



