424 BOTANICAL GAZETTE [JUNE 
ratio to the freezing, so that at the freezing point of the tissue all 
the ice will have disappeared. 
Regarding the function of bud-scales, there is little evidence 
that they function by keeping the water out; neither are they impor- 
tant to the plant as modifiers of temperature. 
Bud-scales have probably been evolved to prevent excessive 
transpiration and to protect the delicate tissue from mechanical 
injury. 
When the bud opens the scales often grow out, forming a tube- 
like structure which protects the young shoot from too great loss 
of water. . 
The wool in such buds as horsechestnut is not to modify the 
temperature, but to protect the young shoot from too great transpi- 
ration. 
CORNELL UNIVERSITY, 
Ithaca, New York. 
ee 
