1914] GATES—XEROPHILY 461 
than for shrubs and trees. No experimentation was performed 
upon herbaceous plants during the winter, for it is known how 
exceedingly small is the amount of water loss from seeds, and as 
the vegetative means of reproduction employed by other herbs are 
December 1911. 
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Relative Humidity. 
Transpiration of Cuttings in the Greenhouse 
Fic. 3.—Transpiration of cuttings of Acer rubrum, Andromeda glaucophylla, 
Chemesdcaie: calyculata, L 
arix laricina, Nemopanthes mucronata, Salix pedicellaris, 
and Vaccinium macrocar pon in the greenhouse 
underground and thoroughly protected from exposure, no com- 
parison could be made with the ericads which retain their plant 
body subject to constant exposure throughout the winter 
The purpose of the winter experimentation, therefore, was to 
obtain a knowledge of the transpiration of several of the shrubs and 
trees, and compare that of the leaf-retaining ericads with that of 
the deciduous shrubs, under winter conditions outdoors and under 
