1 



118 Moore: The study of winter buds 



From the investigations of Fischer (1891) and others, there is ' 

 evidence that certain activities and various metabolic processes 

 take place within the winter bud. Fischer claimed that to the 

 external periodicity revealed in the phenomena of growth there is 

 a corresponding internal periodicity in the processes of metabolism; 

 that, in the buds and young shoots, movements and changes in 

 the reserve material take place during the cool and cold seasons ; 

 and that these activities are dependent not only upon temperature 

 but upon the inherent tendencies of the plant. 



The results of Fischer's investigation would admirably supple- 

 ment those of Askenasy had the latter considered a greater 

 variety of plants. The study of flower buds of Prunus Avium 



m 



alone can scarcely serve as a type for the growth of the leaf buds 

 of all our trees and shrubs. 



The problem of growth m the leaf bud during winter presents 

 two important subjects for scientific research, — the question of 

 growth, in so far as it relates to the enlargement of tissue through 

 the addition of new cells or the stretching of cells already formed, i 

 and the question of leaf content dealing with the formation of ' 

 additional leaf fundaments. These problems are considered in 

 the present investigation. 



Methods 



Material: As a basis for this study, observations and investi- 

 gations have been made on the following twenty-two species, in- 

 cluding seventeen different genera, of the common trees and shrubs 

 of Wellesley, Massachusetts : 



Fagus americana L. (American beech). 



Fagus sylvatica L. (European beech). 



Syringa vulgaris L. (lilac). 



Uhmis americana L. (American elm). 



Ahms incana Willd. (speckled alder). 



Fraximis americana L. (white ash). 



Tilia 



plat 



(b 



PopiiliiS trcmuloides Michx. ( 

 Betiila popiilifolia Marsh. (A 



k) 



