EVEKGREEN TREES IN WINTER. 331 



is 1.3 : 1 : 5.5. The increase of transpiration at the end of 

 experiment was far greater than that in the former phxnt. 

 In Quercus, the variation at the three periods was even greater, 

 viz., 1.9 : 1 : 4.1 (see Fig. 2). 



From these few examples, it is obvious enough that the 

 action of low temperature and other factors did not equally 

 atfect the different species ; that is, in one plant the transpiration 

 was accelerated, while in the other plants, it was not. As 

 will be seen in the curves (Fig. 2), the amount of transpiration 

 in Ternstrœmia at VIII suddenly increases, in spite of the fact 

 that the difference in other periods had been slight. In Thea, 

 the amounts of transpiration at different periods were somewhat 

 different from those of Ternstrœmia. Especially the increase 

 of the transpiration at VIII is not remarkable in comparison 

 with the other species. 



Relation of the anatomical character of leaves upon transpiration. 

 As the plants employed in my experiments had no peculiar 

 anatomical difference, they did not show much difference from 

 one another in the amount of water transpired. It is well known 

 that the mode of passing the winter varies with different kinds 

 of plants ; some close their stomata, while others excrete tannin 

 on the epidermis, by which they protect themselves from ex- 

 cessive transpiration. Although I did not attempt to find out 

 the exact relation between transpiration and the anatomical 

 character of the leaves, still I was able to examine in the plants 

 under observation, the number of the stomata^* and the character 

 of the epidermal wall, which seem to play an important part 

 iu causing the difference of the amount of water transpired. 



1) Since the leaves of the given plants were used for another purpose, I was not able to 

 ascertain the exact number of their stomata. 1 depend therefore for my data on the 

 determinations given by Prof. S. Ike no (Lot. Magazine, Tokyo, Vol. VIII, 18'J4, p. 2Ü1). 



