BEHAVIOR OF PLANTS IN UNVENTILATED CHAMBERS 289 
though much smaller than in the previous comparisons. This reduc- 
tion of the difference in humidity is followed by the nearly complete 
disappearance of the greater height attained by plants under the 
bell jars. 
In some of the sets with Zea, seedlings in the box with still 
air grew thicker and taller; the next week, with a like test, results 
were exactly reversed. The same reversal occurred with Lathyrus. 
Lupinus and Vicia gave a little greater average in height and thickness 
of seedlings in quiet air, Ricinus in moving air, while measurements 
could detect no difference between the two cultures of Triticum. 
Lathyrus and both varieties of Zea showed more individuals dying in 
18 days in moving than in quiet air, while, of the other species used, 
few individuals died and there was no larger percentage of deaths in 
one box than in the other. Persistent differences in the time of 
unfolding of leaves in quiet and in moving air could not be established. 
Using the same two boxes as with the foregoing seedlings, 6 potted 
plants of Coleus were employed, 3 in each box. The plants were each 
about 10 cm. high, each with 4 pairs of mature leaves, and all growing 
well when they were taken from the greenhouse. To make the mois- 
ture conditions more nearly equal in the two boxes, four basins, 20 cm. 
in diameter, were filled with water and set in the box whose air was 
to be agitated by the blower. 
The 6 plants were kept in the dark boxes for 10 days, temperature 
in the two boxes not differing more than 0.4° C, and the temperature 
of the room containing the boxes ranging from 18° to 21.5° C. Exam- 
ination and measurements were made every 2 or 3 days. That the 
pots in the moving air were still in a drier atmosphere than those in 
quiet air was shown by the more frequent watering needed by those in 
moving air. The effects noted in the foregoing cases were still ap- 
parent here, though to a very slight degree. At the conclusion of the 
lo-day period, the 3 plants in moving air showed a total elongation of 
13.7 mm., and had dropped 12 leaves. The 3 plants in quiet air 
showed a total elongation of 14.7 mm., and had dropped 10 leaves. 
Other differences were not apparent. 
Series V. — This series of experiments was carried out in two con- 
stant temperature dark cabinets of about 12 cubic meters capacity 
each, in one of which an electric fan was kept in constant motion, 
while in the other the air was quiet. The temperature for both 
cabinets was regulated for 23°, with an extreme variation of 1° C. 
