346 s. KUSANO : transpiration of 



3. Not only is the transpiration continued in winter in Tokyo, 

 but also the assimilation, as Miyake^^ has recently shown, takes 

 place without intermission in winter, though it is much feebler 

 than in summer ; and the non-cessation of these principal 

 physiological functions in winter would naturally lead us to 

 conclude that the abundance of evergreen trees in Japan is 

 chiefly due to the favourable climate. 



4. The time of minimum transpiration agrees with that of 

 the minimum temperature, and occurs at the end of January. 



5. The difference in the amount of transpiration in different 

 species of evergreen trees becomes smallest at the time of mini- 

 mum transpiration ; and a change in the external conditions, 

 especially in temperature, does not necessarily produce a corres- 

 ponding change in transpiration in different species. 



6. In average cases the amount of Avater transpired by 

 foliage evergreen trees, is one and a half or two times greater 

 than that transpired by conifers if we reduce the amount either 

 to the fresh weight or to the dry weight of the transpiring part. 



7. In diffused light at a temperature of ca. 10°C., the 

 average transpiration of many evergreen trees amounts to 53 

 mgr. per □ dm. per hour. 



The present work was undertaken, at the suggestion of Prof. 

 M. Miyoshi, during the academic year of 1898-1899, and, 

 under his direction, I was able to carry on a large number of 

 experiments. To both Prof. J. Matsumura and Prof. M. 



1) Bot. Centlbl. Bd. LXXX, 1899, p. 172. 



