INTERNAL TEMPERATURE OF LEAVES. 



287 



In this reserve, though starch is the principal material, yet 

 proteid material is present in large amounts. The following 

 analysis by Shibata of the two-year old rhizomes of Phyllos- 

 tachys mitis may be given : — 



Starch 



Reducing sugar 



Non-reducing sugar 



Proteid 



Fat 



Fibre 



Ash 



Undetermined (difference 



Percentage 

 of Dry Weight. 



24 01 



0-95 



4-31 



5-41 



0-61 

 47-32 



8-74 



8-65 



100-00 



We see from this analysis that proteid material is present 

 in considerable amount, and also ash containing, as shown by 

 another analysis, all the necessary minerals. Thus, although 

 we do not know the proportions in which these reserves are 

 required bj^the growing culm, it is probable that in bamboos 

 the growth may go on entirely from reserve and no limiting 

 of the growth from lack of necessary mineral foods may occur. 

 In a previous paper by the present writer (19) it is shown how 

 varied the different cases of growth are. In some the moisture , 

 in others temperature, in others food supply are limiting 

 factors, and in some cases each of these factors may become 

 limiting in turn. We cannot therefore deduce from the 

 reserves in one case what are the reserves and the conditions 

 of growth in another, and some definite knowledge not only 

 of the carbohydrate, but also of the proteid reserve in the 

 trees under consideration in this paper, is greatly to be 

 desired. 



Failing this knowledge it may be said to be fairly probable 

 that when in these trees rapid and general growth takes place, 

 large demands are made upon the mineral supplies obtained 

 from the soil. If this is the case, the trees will require a copious 

 and constant transpiration stream during their growth period 

 to supply the minerals required. That the case of these trees 

 with regard to mineral food supply is quite different from the 

 case of the bamboo is indicated by the fact that at Peradeniya 



