SAP DENSITY AND FREEZING POINTS OF LEAVES. 117 
series of buds. First, those giving rise to the new shoot; 
second, those giving rise to the compound leaf; third, those 
designed for new growth the following year and enclosed 
within the bases of the leaves; and fourth, the so-called 
adventitious buds. The same condition also obtains for 
Cercis canadensis. In Cladrastis a drying up of the new 
shoot was noticed near the tip later in the season, but it 
cannot be said whether this was the result of frost injury, 
or of the drying effect of an unusually warm summer. 
SECTION IV. 
This is a somewhat arbitrary division, but by the death 
of the major portion of the shoot the appearance upon 
recovery was not as natural as that of the former section, 
inasmuch as the new leaves had a more clustered appear- 
ance. As a matter of fact the freeze cannot be said to 
have been injurious, any more than we might say the 
same for a good pruning. By freezing back the ends of 
the new shoots and entirely killing all new leaf growth, 
the frost forced new growth from the basal portion of the 
new shoot, and very largely from the adventitious buds on 
the old woody portion. of the trees and shrubs. The 
appearance of Azlanthus glandulosa, Aralia spinosa, Fraxi- 
nus, Rhus glabra and Rhus typhina, have never been better 
than during the season following the freeze. Recovery has 
been rapid in nearly all cases, and apparently the freeze 
caused very little harm to this group. Aralia spinosa, in a 
clump on low ground, did not flower at all during the season, 
while another clump on higher ground flowered profusely. 
Here again, we cannot definitely place the cause of the 
difference, for normal growth causes might have resulted 
in an off year for flowering, as is the case with many of 
the Rosaceae. 
SECTION V. 
The last list is perhaps the most interesting of all, since 
it shows the effect of the freeze upon the new growth of 
