1906] WIEGAND—BUDS AND TWIGS IN WINTER 377 
several days of warm weather occurring, the peach buds began 
to grow rapidly and uniformly until April 23, one month later, 
when they came into flower. With the apple and apricot the results 
were very much the same. Growth almost ceased November 15, 
and from this time until March 1 the increase was apparent but 
exceedingly slight, amounting to only $ to 1%. Renewal of activ- 
ity began March 1, and from this time until April 23, seven weeks 
later, when the apricots flowered, and eight weeks later, when apple 
buds opened, the growth was very rapid. The curve after growth 
began was not so gradual as in the peach, but became much accel- 
erated just before the flowers appeared. 
Mr. Morcan’s observations were as a matter of fact quite exten- 
sive, but only the above summary can be given here. At intervals 
of one week through the fall, winter, and spring, buds were taken 
from the same tree and as nearly as possible from shoots of the 
same vigor, a large number were measured, and the average taken 
as representing the size at that time. It was found impracticable 
to measure the same bud at different times, owing to the difficulty 
of manipulating the micrometer out of doors on very cold days, 
as well as to the fact that the measurements were liable to be taken 
at different temperatures cach time. A Zeiss cover-glass measurer 
was found the most convenient instrument for the work. From 
the tables thus made a great many curves were plotted representing 
the changes in various fruit trees. The results, however, agreed 
very well, and in the peach, apricot, and apple were as stated above. 
From these careful observations, therefore, contrary to the general 
belief, it seems that fruit buds at least do not grow to any extent 
in winter. Their swelling period is confined in the north to a few 
weeks just previous to the opening of the bud. Regarding our 
forest trees and shrubs no accurate work seems to have been done 
toward the determination of their curve of growth. From casual 
observations, ‘I am inclined to believe that a majority will be found 
to agree with the fruit buds. This seems to be truce of the sugar 
maple, whose buds are practically as large in November as in early 
March, also of the ash, oak, etc. On the other hand, the buds of a 
few plants, as, for instance, Salix discolor, Ulmus fulva, and Ulmus 
scabra, seem to increase in size early in February. However, actual 
measurements are necessary to determine these. points. 
