Moore: The study of winter buds 119 



Hicoria microcarpa Bntton (small-fruited hickory). 



Salix fragiiis L. (brittle willow). 



Salix alba L. (white willow). 



Aesctilus Hippocastanum L. (horse-chestnut). 



Querctis alba L. (white oak). 



Quercus rubt-a L. (red oak). 



Picea excelsa Link (Norway spruce). 



Liriodendron Ttilipifera L. (tulip-tree). 



Rhododoidron maximum L. (great laurel). 



Philadelplms (mock orange). 



Determination of bud content 



For the study of leaf content, normal branches, upper and 

 lower ones from various parts of the tree or shrub, were taken and 

 studied during the months of November and December, 1905 and 

 1906. A long pruning shears was used to reach the upper 

 branches. The number of nodes was counted and recorded for 

 each season's growth, two and, where practicable, three years 

 back. By this method a record of the number of leaves which 

 were developed during those seasons was obtained. The terminal 

 or upper axillary bud of each shoot, the nodes of which had been 

 counted, was examined with a dissecting microscope, and the 

 number of leaves found in the bud was noted. 



Field observations on growth 



Observations on the growth of the bud were carried on during 

 all of the winter and spring months. Ten normal buds of each 

 genus were marked with a nurseryman's wooden label. Dur- 

 ing the latter half of November, 1905, and each month thereafter 

 until the unfolding of the leaves in April or May, these buds were 

 measured for the greatest length and the greatest diameter in each 



Measurements in length were made with a steel spacing 



dividers; measurements in diameter, with a micrometer screw cali- 

 per graduated to O.QI mm. During the months of February, 

 March, and April, measurements were made twice a month, once 

 at the beginning and once at the close. Data resulting from these 

 measurements, about 3000 in all, form the basis of the curves of 

 growth as well as of the deductions on dormancy and growth in 

 the gross study of buds. 



