Variation of Water in Trees. 113 



time on, the curve descends at a more gradual rate until 

 December, when it suddenly drops to its minimum depres- 

 sion, which evidently occurs in January. 



PERIODS OF CESSATION OF GROWTH. 



As, upon theoretical grounds, the tissues contain most 

 water when the growth is most active, data which will 

 enable us to fix accurately the limiting periods for the sea- 

 son's growth, will have an important bearing upoD this 

 question. Mr. W. E. Stone, l accepting the completion of 

 terminal buds as marking completion of the longitudinal 

 growth for the entire year, has obtained the following data, 

 as establishing periods limiting growth in trees for the 

 latitude of West Point, New York, 41° 23' N. :— 



June 1st. 

 Acer saccharinum. Wang. 



" rubrum. L. 

 Amelanchier canadensis. Torr & Gr. 

 Carya alba. Nutt. 

 Fagus ferruginea. Ait. 

 Fraxinus americana. L. 

 Hamamelis virginica. L. 

 Kalmia latifolia. L. 

 Populus tremuloides. Michx. 

 Quercus alba. L. 



" bicolor. Willd. 

 " coccinea- Wang. 

 " prinus. L. 

 Sambucus pubens. Michx. 

 Tilia americana. L. 

 Ulmus americana. L. 

 " fulva. Michx. 



June 15th. 

 Betula lenta. L. 

 Carpinus americana. Michx. 

 Castanea vesca. L. 

 Juglans nigra. L. 

 Lindera benzoin. Meissner. 

 Morus rubra. L. 

 Ostrya virginica. Willd. 

 Prunus cerasus. L. 



1 Bull. Torrey Bot. Club., xii. 8,83. 



8 



