206 ANNUAL BEPOET SMITHSONIAN INSTITUTION, 1916. 



with M. Cliou, in directly obtaining certain alkaloids, hydrolyzing 

 in vitro the albumens themselves in the presence of formaldehyde. 



It therefore seems well proved that the alkaloids have their origin 

 in the plant by cyclisation of the products of decomposition of the 

 proteins; and, by analogy, it is justifiable to attribute the same 

 origin to all similar compounds. 



In resume, we observe a complete parallelism in the two gi'and 

 divisions of organic compounds, between the form of their molecular 

 structure and the role they play in the plant organism. Only com- 

 pounds with open chains are capable of maintaining life in this 

 organism, while compounds with closed chains, found in abundance 

 in certain plants, are merely waste products, without nutritive 

 value, rendered inactive by the fact of their cyclisation. An ideal 

 plant ought to contain none at all. But a serious objection is at 

 once raised to this conclusion. Any chemist or botanist will make it. 

 He will say: In the list of substances which, in the plant, do not 

 contribute to the formation of its protoplasm, you have omitted the 

 most important, cellulose, that material, morphologically indispen- 

 sable, which, in all plants, forms the cell walls and ducts and plays 

 a fundamental role in the mechanical protection of the protoplasm 

 by affording the covering needed for its organization into more or 

 less rigid and resistant tissues. 



It seems indispensable, continues my opponent, that the substance 

 upon which this function devolves should possess a chemical sta- 

 bility sufficient to resist the multiple activities carried on within the 

 plant. It must be independent of the general action of metabolism. 

 If the ideas that you have developed are correct, they say, this 

 independence would result from its molecular structure, and cellu- 

 lose, like every other compound that the plant excludes from its 

 vital activities, would possess the cyclic structure. But all chemical 

 treatises place cellulose, as well as starch, among the open-chain 

 compounds; and this fact alone is enough to overthrow the entire 

 basis of your theory. 



I recognize that this objection would be unanswerable if it rested 

 on solid ground; that is to say, on an exact knowledge of the con- 

 stitution of cellulose. But this constitution has not yet been de- 

 termined, and the analogy with starch is not enough to establish 

 it. I believe, on tlie contrary, that cellulose should be far removed 

 from starch in the classification and be placed among the com- 

 pounds of cyclic structure. A series of experiments that I have 

 carried on with MM. Ramseyer and Bouvier offer proof of what 

 I advance. These experiments bring out the following consider- 

 ations: 



The chemical phenomena which cause tlie decomposition of the 

 plant after its death vary according to the conditions in which 



