354 SMITH APPLICATION OK THE THEORY Ol 



will occur, and we may confine ourselves to the consideration of 

 t he physical factors necessary for the translocation and working 

 up of these materials. 



T< mperaiun . 



Of these temperature is of course very important. All the 

 chemical changes which take place in the synthesis of proto- 

 plasm from the above substances are not at present known, 

 but it is quite probable that as far as regards their relation 

 to temperature they do not differ essentially from those 

 -impler syntheses which take place during assimilation. 



F. F. Blackman (2) has pointed out that the relation of tin- 

 assimilation of certain leaves to temperature when light and 

 1 < » . supply are in excess follows a definite rule. This is that 

 hi increase of temperature of 10 : 0. roughly doubles the amount 

 of assimilation. He notes that certain numbers obtained for 

 respiration and other widely different metabolic changes agree 

 in following this numerical rule, and points out that this rule 

 also applies to certain slow organic changes taking place in 

 vitro, such ms the saponification of esters and other processes 

 which resemble the changes in the plant. Me then suggests 

 thai this law is primarily applicable to changes in the cell as 

 fl ell as iii the test-tube and noes on to show how this applica- 

 tion may be made to the process of assimilation, of respiration, 

 and with certain qualifications to that of growth also. Tt is 

 quite probable therefore that if all the synthetic processes 

 which are involved ingrowth wcvr known, and that if they 



could '"• isolated and carried <»n in vitro, each one of them 

 would follow the same rule. It follows that if all the food 

 materials and the water are iii good supply we should expect 



th as a whole Id exhibit this general relation to temper 



ature and to inorease with the temperature up to the death- 



pomt of protoplasm 



That growth show- on the other hand B true temper « I U I « 

 optimum aftei which further increase ol temperature causes 



be supposes, due to secondary causes which 



