106 MISSOURI BOTANICAL GARDEN, 
ever, the case under consideration represents the reverse 
process, since the weather to which these plants were being 
subjected was gradually adapting them to warmer instead 
of colder weather. It would seem then, on the face of 
things, that frosts occurring in the spring find the plants, 
as a rule, preparing for the growing season and warmer 
weather, while those occurring in the fall and at the close 
of the growing season, find the plants tending to acclimatize 
themselves to the approaching cold weather. There should 
be no doubt, then, as to the period of the year in which a 
frost is the more destructive. 
The immediate condition of the weather around the 24th 
of April, 2. e., the period from the 20th to the 29th deserves 
some attention, and the following temperatures, maximum 
and minimum, are here given, and are well illustrated by 
the appended diagram :— 
Bee tomo 
= 
o 
0 —_—— iY 
se 
do . wre 
ao 4 2a a2 ay as 46 a? 48 “2 zo 
in which the ordinates are the temperatures recorded for 
the ten days represented by the abscissae. The weather for 
ee ee 2: 
