EVERGREEN TREES IN WINTER. 345 



temperature many degrees below 0°C. rendered the absorption of 

 water more difficult. Owing to the deficiency of water the plant 

 lost their turgidity of tissue and consequently became wilted. 

 As the temperature after daybreak gradually increased and reached 

 about 0°C. or above, the absorption of water became gradually 

 easier, until after about an hour, it attained its maximum. 

 When a sufficient quantity of water was thus taken up, the rate 

 of absorption became slower and constant, and the wilted branches 

 gradually resumed their norm^al position and stood perfectly erect. 



VII Summary. 



The results of my investigations may be briefly summarized 

 as follows : — 



1. The evergreen trees indigenous to Japan used in my 

 experiments transpired in winter in Tokyo, an average quantity 

 of, at least, 0.48 gr. per D dm. per day (with the exception of 

 conifers), or 16.58 gr. per 100 grams of fresh weight in foliage 

 trees, and 8.18 gr. in conifers per day. 



2. In the southern part of our country where the climate 

 is milder (the mean temperature at Nagasaki in January being 

 5.°C.), the intensity of transpiration would undoubtedly be greater. 

 But the contrary is no doubt the case in the northern part, 

 especially in the island of Yezo, where the winter is severe (the 

 mean temperature at Sapporo in January being -6.3°C.), and the 

 plants must protect themselves from a great loss of water ; and 

 perhaps we may in their case expect the same occurrence of a 

 minimum transpiration, as has been observed, for example, in 

 Germany, 



