376 BOTANICAL GAZETTE [JUNE 
point without well-developed lateral organs, and can therefore be 
protected more economically by being sunk in a pit produced by 
a ring-like growth of cortex and cork, as is commonly the case. 
This pit is then closed at the mouth by an ingrowth of the cork 
itself, as in Gleditschia, or by a feltlike mass of hair, as in Robinia 
and other species. . 
In the case of the large buds with the shoot considerably advanced 
in growth, the bud-scale method seems the only feasible way of 
' covering them. Another advantage in this method lies in the tele- 
scopic expansion of which scaly buds are capable early in the season 
while unfolding. Growth is thus permitted, but at the same time 
the protective qualities are not lost. In the maples and_horse- 
chestnut the tube formed by the enlarged scales often reaches the 
length of 2 to 8°". By this means buds may open early in the spring 
and still be protected from excessive transpiration. Scaleless buds 
usually remain nearly dormant until later in the spring when the 
weather conditions are not so severe. 
PHYSICAL PHENOMENA OF BUDS AND TWIGS WHEN NOT FROZEN. 
The scaleless buds of the indefinite growing trees and shrubs 
grow very little before or during the winter. In the autumn the 
very limited growth is soon stopped by the advent of cold weather, 
and from this time until late spring scarcely any change can be 
detected. With the scaly buds however it is otherwise. From 
the inception of the fundament in July or June until cold weather 
there is a very considerable growth resulting in the buds of various 
sizes found upon the different species of trees during the winter. 
Little accurate work has been done towards determining the char- 
acteristics of this growth, but the results obtained in our laboratory 
by W. M. Morcan during the fall of 1901 seem to show that in 
the case of fruit trees the growth is very uniform and gradual up 
to about November 15. In some cases slight fluctuations occurred 
which could not be accounted for, and in one or two instances these 
seemed periodic; but on the whole there appeared neither accel- 
eration nor retardation until the time mentioned, when the increase 
in size ceased quite abruptly. From the middle of November until 
March 1 there was no growth in peach buds, the curve remaining 
almost exactly horizontal and fluctuating very little. On March 23, 
