EVERGREEN TREES IN WINTER. 349 



EXPERIMENTAL DATA. 



I. Transpiration by Direct Insolation of Pot-Plants. 



With regard to the temperature and relative humidity which are referred 

 to in the following experiments, I adopted the observations made by the 

 Centra] Meteorological Observatory of Tokyo, which is situated at a distance 

 of one and a half miles from our laboratory. Both places are almost similar 

 not only in position but also environment, and the hourly observation shows 

 that the air temperature in both places are nearly the same, as will be 

 seen from the following comparison. 



Sept. 27th. At Bot. Gard. At Obs. Sept. 29tli. At Bot. Gard. At Obs. 



3p.m 23°C 23.6°C. 10 p.m 16.2 16.4 



4 22.5 22.4 11 16.2 16.3 



12a.m 16.2 16.3 



28th. 1 p.m 16.25 16.3 



lOa.m 21.5 21.5 2 16.5 16.5 



11 22.75 22.3 3 15.75 15.9 



12 23.5 22.8 30th. 



1 p.m 23.5 23.9 7 a.m. 17.5 17.8 



2 23.5 24.6 8 20+ 20.1 



3 23.0 23.5 9 21.5 21.8 



4 21.75 21.8 10 23.5 23.4 



5 20.0 20.2 11 24.75 24.1 



In the column representing the total amount of transpiration in the 

 following tables, I have given the total daily transpiration ; and in the 

 column of average of daily amount of transpiration, the mean value for each 

 day. In the succeeding three columns, I have given the value of trans- 

 piration, calculated from the average of the daily amount of transpiration 

 and reduced to the area, fresh weight and dry weight, of the transpiring 

 parts respectively. The amounts were expressed all in gram. 



