40 



nine from cupreine. Cupreine is an alcaloid found in the 

 bark of Remija pedunculata Flueck. 



It lias consequently been proved that alcaloids found in 

 différent gênera of plants can even outside of those plants 

 been transformed to each other, why should not a plant 

 be able to transform alcaloids formed by itself? 



Some occasional experiments with strychnos-species hâ- 

 ve gïven me indications of such a transition from strych- 

 nine to brucine in the strychnos leaves. 



Therefore to conclude, it may be admitted that: Gincho- 

 na trees form their alcaloid in the leaves, transport it to the 

 bark where it is stored either in its original form or after 

 having been changed to another alcaloid. 



Such transitions from one substance to another are by 

 no means rarely met with in plants physiology, it onlyneeds 

 to be reminded of the behaviour of starch and sugar. 



It is self- évident that thèse experiments do'nt exclu- 

 de the possibility of a formation of alcaloids in the bark 

 itself, yet it seems to me that thèse experiments together 

 with the reasoning stated above, make it plausible that any- 

 how tins will be of very much less importance than that 

 formed in the leaves. 



Of the previously published analyses a séries by Mr. v. 

 Leersum showirg that trees with a yellowish foliage con- 

 tain a lesser percentage of alcaloid than those with a dark- 

 gi een one is of course much in f'avour of our theory. 



Thèse experiments show that it is of prime importance 

 for the Cinchona -planter to do ail in his power to obtain 

 a rich foliage on his trees, a proceeding which in the last 

 years lias been follôwed in the Cinchona-plantations of 

 the Dutch Government, 



It may not be devoid of interest to state in what di- 

 rection the author thinks further experiments will have 

 to proceed. 



