460 BOTANICAL GAZETTE [JUNE 
preserved in glycerin-alcohol, later sectioned, and stained with 
iodin green to show the area of the conducting system. 
By means of the lithium nitrate method, which consists of 
cutting off the lower ends of leafy stems under a o.5 per cent 
aqueous solution of Li(NO,)., allowing the stems to take up the 
solution, removing after certain intervals, and cutting immedi- 
ately into 1 cm. lengths, testing these pieces in the spectroscope 
for the presence of lithium, a knowledge of the rate of conduc- 
tion under different conditions was obtained. This method only 
approximates the rate of conduction in rooted plants, which could 
not be used because of inability to know when the lithium nitrate 
would be absorbed by the roots. 
The difficulty of examining the stomates of Chamaedaphne by 
the ordinary method of stripping and the consequent uncertainty 
of its results with this species led to the abandonment of work on 
stomates until the publication of a new method (Mo.iscH 35) 
opened the way for experimentation upon this pertinent question. 
The “infiltration method,” as it is called, depends upon the fact 
that when a leaf is wetted with a penetrating liquid, such as abso- 
lute alcohol, xylol, or turpentine, and held up to the light, it becomes 
translucent as soon as the liquid has penetrated the leaf. The 
relative time that it takes the leaf to become translucent after the 
application of xylol indicates whether the stomates are open or 
closed, because the more the stomates are open, the easier and 
quicker will the liquid penetrate the tissue and the sooner will it 
become translucent. A “normal” time must be determined for 
each species upon which to base deviations. Xylol was used 
throughout the present work, and the results were checked up with 
absolute alcohol and turpentine. As the method is so very simple, 
it can be employed in the field and several determinations made 
each time. The results were remarkably uniform. 
EXPERIMENTATION DURING THE WINTER 
Transpiration 
During winter the transpiration of the plants of the region is 
reduced to a serviceable minimum which, however, is not zero 
(cf. Kusano 26). For herbaceous plants the minimum is lower 
