414 BOTANICAL GAZETTE [JUNE 
a supply of water sufficient to offset that lost in transpiration. In 
winter, however, the cells are inactive, and on account of the cold 
the osmotic force is much decreased, so that the cells find it impos- 
sible to resupply quickly the transpiration water when this function 
is very great. 
That loss of water beyond a certain point is detrimental to the 
cell needs no further demonstration. It has been shown that each 
cell demands a certain percentage of water, depending mainly upon 
its activity and water content, in order to maintain its life-prop- 
erties. If transpiration even for a short time reduces the water 
in the cells of the bud below the critical percentage, the cells will 
cease to remain alive. 
During January 1gor, I cut some twigs of horsechestnut, stripped 
off the bud-scales from some of the buds, and exposed the whole 
to an outside temperature of —18° C. to —12.3° C. for 24 hours, 
after which the twigs were placed with their cut ends in water in 
the greenhouse for further development. The buds all lived, although 
those without bud-scales were the first to commence growth. Sub- 
sequent experiments show that the reason why none died was because 
the exposure to the dry air was not long enough. On March 1 
of the same year, buds of the black cherry, Crataegus punctata, 
horsechestnut, lilac, apple, and Pinus Laricio while still on the tree 
were deprived of their scales and each divided into two lots. One 
lot was left naked, the other was varnished completely with Venice 
turpentine to prevent loss of water. When the normal buds were 
opening May 8-10 it was found that both varnished and naked 
buds were all dead except on Pinus Laricio. On this plant the 
naked buds were all dead, but the varnished ones were alive, and 
later all developed into normal shoots. 
The varnished buds in all cases seemed to be all sound and turgid 
until warm weather and time for swelling came, when they seemed 
to decay rapidly, and in no case except the pine did any swelling 
occur. I suspect that death here was due to the retardation of res- 
piration owing to the lack of oxygen. The pine is normally closely 
surrounded by resin without a space inside as in horsechestnut, 
and possibly some other way is here provided for obtaining Oxy- 
gen. The pine, therefore, is the only one of the series in whic 
