342 s. KUSANO : tkanspieation of 



ill the latter cases (expts. 22 and 26) is reduced to one fourth 

 of that in former case (expt. 1), and in Daphniphyllum macro- 

 podum as well as in PUtosporum Tobira, to one third ; while 

 Ternstrœmia japonica transpires very sluggishly without showing 

 any noticiable difference during the experiments in both high 

 and low temperatures. This slight variation in the quantity of 

 transpiration of Ternstrœmia japonica under such condition of 

 temperature was ceteris paribus a noteworthy phenomenon during 

 these experiments ; thus again, the amount of transpiration, under 

 air temperature of 9.2-9.°C. and water temperature of 9.2-9.6°C. 

 in December was 30.56 mgr. per D dm. per hour, while at the 

 lower temperature, both of air and water, of 2.6-2.8 and 1.5°C., 

 24.84 mgr. of water was given off. The cause of this slight 

 difference becomes evident when we consider the presence or 

 absence of stomatal transpiration. 



Lastly let us describe here, for the sake of comparison, some 

 experiments made, in the midst of summer, in a room under 

 diffused daylight. At that time the weather was very wet and 

 almost rainy, the relative humidity indicated being 80-909^, or 

 even more. Helianthus tuberosus with 56 leaves, standing in a 

 glass vessel filled with water, transpired 2.511 grams per D dm. 

 in the interval between 12 m. and 6 p.m. on the 25tli of August, 

 and 3.349 grams per D dm. between 6.20 a.m. and 5.20 p.m. on the 

 next day. The amount of water transpired by the space of a square 

 decimeter of the leaves in an hour was, therefore, 0.418 gr., in the 

 first, and 0.304 gr., in the second experiment. Thus with the 

 typical evergreen leaves observed in the cold winter on the one 

 hand (at a temperature near 0°C., — Table IX experiment 21-27) 

 and with the typical summergreen leaves observed in the midst 

 of summer on the other hand, the relative difference of trans- 



