THE INFLUENCE OF AIR-CURRENTS ON TRANSPIRATION. 
BY MAUD A. BROWN. 
This is intended merely as a brief preliminary report on experiments 
now under way to show the influence of air-currents on transpiration. 
They have arisen from a study of transpiration in general, during which 
the conviction has grown that one very important factor has been largely 
neglected. Therefore this has been made the main point of attack while 
side lines of investigation have been carried on in which it has been 
attempted to vary one factor at a time, i. e., light, temperature and 
humidity, and to determine if possible the relative influence of each 
on transpiration, and their importance as compared with that of air- 
currents. They are not complete, but so far, they indicate that humidity 
of the air is the most important of the three mentioned. 
These experiments have been carried on in doors, because of the pos- 
sibility of controlling conditions. The air-currents were produced by 
an electric fan, different velocities being secured by placing the plants 
at varying distances from the fan. 
Elongated boxes, open at both ends, 15x18 inches by 3% feet, were 
used, one end of glass, that the light problem might be eliminated. The 
fan was set in the dark end, the plant in the light, and at varying dis- 
tances in front. 
The wind velocities at these stations- were determined by a small mill 
anemometer, the humidity and temperature by Green ’s standard psychro- 
meter, and the air pressure by an aneroid barometer. 
The plant selected was Clivea, one of the Amaryllidaceae. It has the 
advantage of having long stiff leaves, which will stand erect under the 
current, so that no stems need be used, the whole surface being trans- 
piring surface. The epidermis is easily removed and the stomata are 
of good size. Leaves of as nearly as possible the same age were used 
and sealed into slits in the corks of wide mouthed bottles. 
Four stations were established. I. 1% feet in front of fan, wind 
velocity 800 feet per minute. II. 3% feet in front of fan, wind velocity 
300. III. 7 feet in front of fan, wind velocity 205. The fourth sta- 
tion in quiet air of the laboratory. 
