340 BOTANICAL GAZETTE [MAY 
as many as 50 per cent of the flower buds may be killed; conse- 
quently they may be placed in the semihardy group for a con- 
siderable portion of the state. The trees of each of these varieties 
from which material was obtained are about eight years old, and 
are growing in a dark, rich, silt loam soil. All are under clean 
cultivation without cover crops. 
In making the moisture determinations, fruit buds were collected 
at the Fruit Breeding Farm in glass weighing dishes provided with 
closely fitted covers, at intervals varying from one to two weeks 
during the months from November 2 to March 31. On the evening 
of the same day the dishes containing the buds were brought into 
the laboratory, carefully weighed, and placed in an electric vacuum 
oven at 95°-98° C., with the pressure reduced to 8.5 cm. of mercury. 
The buds were kept in the oyen until successive weighings indicated 
that all of the water had been removed from the tissues. In a 
determinations made before the middle of January it required about 
72 hours to bring the buds to constant weight. After this date 
the desiccation began to take place more rapidly, and during the 
latter part of February the moisture could be completely evaporated 
in 24 hours. The extremely small size of the buds made it practi- 
cally impossible to secure large samples for these determinations, 
since 200-250 buds were required for a single gram, wet weight. 
In the dehydration experiments the usual method was followed, 
in which the buds or twigs were placed in sealed chambers over 
sulphuric acid. 
Relative degree of dormancy in hardy and semihardy forms 
In determining differences in the degree of dormancy between 
the hardy and semihardy varieties, twigs were cut at intervals 
between October 3 and March 5 inclusive, and placed in water in the 
laboratory or greenhouse. In this way the fruit and flower buds 
were exposed to ordinary room temperatures, and careful notice 
was taken of all visible changes undergone, as well as the time 
required for anthesis. The results of these studies are shown in 
table I. 
It is quite evident from these data that the buds of the semi- 
‘hardy varieties possess a very light dormancy, for when placed 
