SYNCHRONISM IN PLANT STRUCTURES 



JOHN MUIRHEAD MACFARLANE 



University of Pennsylvania 



In all departments of botanical inquiry it is becoming increasingly 

 evident that wide observation and exactness of record are indispens- 

 able, if we are to reach wide and exact conclusions as to plant life. 

 So the carefully tabulated experiments of Koelreuter, Gaertner, 

 Herbert, Darwin, Mendel, Vilmorin and others regarding plant cross- 

 ing during the past century were the appropriate starting points for 

 the more extended and exact results that are now being secured by 

 plant breeders. 



The characteristic also of exact and correlated behavior on the part 

 of plant organisms powerfully impressed the writer as he advanced in 

 his studies of parent and hybrid types, from 1889 onward. Not the 

 least striking of his results were those bearing on the relation of 

 plants to environal atmospheric agents or stimuli, such as light, heat 

 and water supply.^ So alike as regards constitutional vigor and 

 period of blooming as for chemical nature, color, and odor of hybrids, 

 it was concluded that each detail was more or less exactly between 

 that of the parents; "while some vary to a greater or less degree from 

 one or other parent." Impressed, therefore, by such conditions, the 

 writer has observed closely, during a period of twenty-five years, the 

 action of those environal agents which we speak of collectively as 

 climatic conditions, and the reaction of plant parts to these agents, 

 with a view to determining how exactly each plant organism is corre- 

 lated with its environment. This line of inquiry has received con- 

 siderable attention during the past seventy-five years, under the 

 term "phytophenology." But the study, as well as the results se- 

 cured, have been very largely ignored by botanists, or even ridiculed 

 by some as yielding no conclusions of value. We would emphatically 

 assert that few lines of investigation will compare with this if the 

 studies are prosecuted in exact manner, and are planned so as to cover 

 a definite field. 



The present communication may be suggestive in connection with 

 future possible developments at such an experimental institution as 

 the Brooklyn Botanic Garden, which has already had so successful a 

 history under its able director. 



1 Gard. Chron. 9': 753. 1891. Trans. Roy. Soc. Edin. 37: 255. 1892. 



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