396 BOTANICAL GAZETTE [JUNE 
Taking up these in turn, if the cells were so unprotected as to 
be capable of absorbing water in this way, they would be expected 
to lose a large part again when dry conditions returned, and thus 
quickly following frosts alone could do harm. ‘There is also con- 
siderable doubt whether sufficient water would be absorbed by 
the cells to cause any perceptible difference in sensitiveness. Water 
at winter temperatures absorbs air very little, and especially after 
having fallen in the form of raindrops it may be considered as nearly 
saturated. The air in the leaves would probably be absorbed very 
little, if at all, although compression of the air due to capillarity 
might allow some water to enter. If the thawing tissue has its 
spaces filled with water instead of air, this will not necessarily cause 
harm. In experiments on leaves it was found that only the ivy 
leaf was unable to recover when the spaces were filled with water. 
Many leaves allow the water to evaporate and then become normal. 
Mechanical injury is not probable since the air spaces of the tissue 
would be elastic enough to overcome the compression of the expand- 
ing ice between the organs, and after the tissue froze slight pressure 
from the outside on the compressed cells would do no more harm 
than the pressure of the ice masses within ordinary tissuc. 
However, the greatest objection to this theory, it seems to me, 
lies in the fact that protection against moisture might be obtained 
in a much simpler manner. The embryonic tissue might be densely 
clothed with strigose hairs, or densely glaucous, either of which 
would cause the rain drops to roll off without wetting, at the same 
time allowing gas-interchange to continue; or a coating of resin 
would effectually prevent all danger of water absorption. All 
of these devices are more simple than the elaborate system of bud- 
scales found on many trees. On the other hand, the wool produced 
on many buds would tend directly to retard the drying of the bud 
surface. 
The result of an experiment may here be given. During the 
winter of 1902, about January 24, several buds of Acer platanoides, 
deprived of their scales but still remaining on the tree, were each 
inserted in a rubber pipette-bulb previously filled with water. The 
neck of the bulb was then fastened firmly around the twig by means 
of twine. The experiment was allowed to continue about one 
