FOLIAGE-LEAVES AND THE CHLOROPHYLL FUNCTION. 529 
Jloribunda and O. vespertilionis, Phenix dactylifera, Trillium 
erectum, T. erythrocarpum, and Zea Mays. 
Arisema triphyllum, Schott. 
The form and habit of this species are such that it lends itself 
very readily to the necessary series of experiments. On this 
account a much wider range of tests were made with it than with 
any of the other plants mentioned, and altogether it formed the 
subject of 46 experiments. The large tuberous corms were 
gathered from the soil in woods in October, and placed in a cold 
house until February 1st, when they were placed in a temperate 
room, beginning growth two weeks later. Ordinarily the plant 
sends up one or two leaf-stalks, 30 to 50 em. in height, bearing 
the trifoliate lamiua, with an area of 100 to 250 sq. cm., and a 
single scape, 20 to 40 cm. in height, bearing a spadix enclosed by 
a hooded overarching space. The hood contains a large proportiou 
of chlorophyll and sustains in greater part the functional activity 
of the leaf, and exhibits similar reactions to light and modified 
atmospheres. The correlation of growth is such that the scape 
and inflorescence attain full size within ten days from the open- 
ing of the bud, and the greater part of the leaf-expansion follows 
in the next ten days. During the first 10 days the starch stored 
in the corm is drawn upon to furnish an increasing amount of 
material for the growth of the aerial organs; during the next 10 
days a decreasing amount is drawn from the corm, and usually 
afier that time a stream of plastic material sets in the opposite 
direction from the laminz, which is in part stored in the corm 
and in part used in the development of the lateral offshoots, 
which begin development at this time. 
Effect of an Atmosphere free from CO,.—Buds which had 
attained a height of 10 cm. were brought through an opening in 
a glass plate allowed to rest upon the top of the pot in which the 
plant was grown. The opening around the bud was securely 
sealed by means of wax, moulding clay, or the following device :— 
A cork stopper was perforated with an opening larger than the 
ultimate size of the sheathing bases of the petioles, and the upper 
part of the opening was enlarged to form a cup-shaped cavity. 
After the cork had been saturated with paraffin it was placed 
. in the glass plate and enclosing the bud, the bottom of the cup- 
shaped cavity covered with a loose layer of asbestos or glass-wool, 
and over this was poured a layer of mereury Š mm. in thickness 
