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THE 



Canadian Record of Science, 



MONTREAL. 



VOLUME I. NUMBER 4. 



I. Distribution of the Reserve Material of Plants 

 in Relation to Disease. 



By D. P. Penhallow. 



By reserve material we understand all those proximate consti- 

 tuents of plants which are either directly or indirectly the pro- 

 duct of assimilation, and which are stored up in solid or liquid 

 form to meet some future requirements of growth. 



It is essential for us to bear in mind that, such material being 

 the result of an assimilative function which is dependent upon the 

 presence of chlorophyll and the action of sunlight, it can be found, 

 primarily, only in those parts of green plants which grow under the 

 normal influence of light; and, secondarily, also in those parts of 

 green plants which are normally excluded from the light, and to 

 which it has been transferred from the organs where it is formed 

 by secondary processes. It follows from this,that all such material 

 must be absent from colorless parasites, except in so far as they 

 may have taken up the digested material of their hosts and rede- 

 posited it in their own tissues, and from all saprophytes. It will 

 also follow that, whatever operates to influence the digestive pro- 

 cess in green plants must have a direct bearing upon the amount 

 of reserve material finally deposited, as well as the tissues in 

 which it is stored. 



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