BOTANICAL ADDRESS TO THE BRITISH ASSOCIATION. 13 



been known, and Bokorny has shown that this can be 

 utilized by plants in the production of starch. 



The precise mode of the formation of form-aldehyde in 

 the process of assimilation is a matter of dispute. But it is 

 quite clear that either the carbon dioxide or the water, which 

 are the materials from which it is formed, must suffer dis- 

 sociation. And this requires a supply of energy to accom- 

 plish it. Warington has drawn attention to the striking 

 fact that in the case of the nitrifying bacterium, assimilation 

 may go on without the intervention of chlorophyll, the 

 energy being supplied by the oxidation of ammonia. This 

 brings us down to the fact, which has long been suspected, 

 that protoplasm is at the bottom of the whole business, and 

 that chlorophyll only plays some subsidiary and indirect 

 part, perhaps, as Adolph Baeyer long ago suggested, of tem- 

 porarily fixing carbon oxide like haemoglobin, and so facili- 

 tating the dissociation. 



Chlorophyll itself is still the subject of the careful study 

 by Dr. Schunck, originally commenced by him some years 

 ago at Kew. This will, I hope, give us eventually an 

 accurate insight into the chemical constitution of this impor- 

 tant substance. 



The steps in plant metabolism which follow the synthesis 

 of the proto-carbohydrate are still obscure. Brown and 

 Morris have arrived at the unexpected conclusion that ' cane- 

 sugar is the first sugar to be synthesised by the assimilatory 

 processes.' I made some remarks upon this at the timej^" 

 which I may be permitted to reproduce here. 



" The point of view arrived at by botanists was briefly 

 stated by Sachs in the case of the sugar-beet, starch in 

 the leaf, glucose in the petiole, cane-sugar in the root. The 

 facts in the sugar-cane seem to be strictly comparable.^' 

 Cane-sugar the botanist looks on, therefore, as a ' reserve 

 material.' We may call ' glucose ' the sugar ' currency ' of 

 the plant, cane-sugar its ' banking reserve.' 



" The immediate result of the diastatic transformation of 



adjourn. Chem. Soc, 1893,673. iTKew Bullelin, 1891,3 5-41. 



