Moore : The study of winter buds 



137 



Hartig (1861) observed that the duration of time during which 

 this transportation of reserve food takes place is about the same 

 for all trees, two months in all, but that the beginning of this 

 activity varies in different trees. Activity begins about the middle 



of February in Acer, and about the 



March in Q 



w 



Baranetzky (1873) suggests that the power of bleeding, which 

 is so frequently observed in plants, is a direct expression of the 

 internalchanges which are repeated every year in hibernating trees. 



Halsted 



in the pistil and in the filaments of stamens, organs which in early 

 winter do not contain this reserve food. 



It is possible that as a result of these metabolic processes 



Figure J. Picea excetsa. Curves of growth of the buds iji length and diameter 



growth is induced, although ever so slowly, and serves as a prep- 

 aration for the sudden and rapid development of the young leaves 

 and embryonic parts of the bud m the spring. 



There are many difficulties necessarily in the way of determin- 

 ing absolutely any increase due to the stretching of cells in the 

 leaf or in the leaf fundaments of the bud. In comparing buds for 

 the different months of the rest period, slight variations in size and 

 in stage of development must be expected, but irregularities in this 

 respect are minimized by a comparison of a large number of sim- 

 ilar buds. 



The median sections of buds and meristematic points illustrated 



