INDIVIDUAL VARIATION IN THE ALKALOIDAL CON¬ 
TENT OF BELLADONNA PLANTS 
By Arthur F. Silvers, 
Chemical Biologist , Office of Drug-Plant and Poisonous-Plant Investigations, Bureau 
of Plant Industry 
INTRODUCTION 
It has long been recognized that a necessity exists for the improvement 
of the important medicinal plants. Within recent years agricultural 
science has been largely concerned with the improvement of crops by 
the application of the methods of plant breeding, but thus far practically 
no attempts have been made to extend these methods to drug plants 
with a view to improving their medicinal qualities. The chief aim in 
applying such methods should be to increase the active medicinal con¬ 
stituents rather than to improve the appearance of the plants. That 
the amount of a chemical constituent in a plant can be favorably modified 
by selection has been amply proved by work which has been done on the 
sugar beet, and there is reason to believe, therefore, that similar efforts 
with the economically important medicinal plants will be attended with 
success. 
One of the first steps necessary to inaugurate such a plan is to deter¬ 
mine the variation of the active constituents in individual plants and the 
extent to which such variation is influenced, if at all, by the various 
factors affecting the growth and cultivation of the plants. This article 
deals entirely with such a study. The results herein set forth furnish a 
basis for the application of the principle of selection as the next step in 
the solution of the problem. 
Atropa belladonna was selected as a suitable plant with which to work, 
since it is probably the most important of the group of solanaceous 
plants which depend for their therapeutic action on mydriatic alkaloids. 
The supply of this plant in the wild state is largely exhausted and future 
supplies must necessarily depend on cultivation. The alkaloids which it 
contains can be definitely determined by chemical assay, which is a dis¬ 
tinct advantage in a problem of this kind. 
The writer wishes to emphasize the fact that the work thus far done 
constitutes but a preliminary step toward the application of the methods 
of selective breeding, which has already been begun. Considerable 
interest attaches to the results presented in this article because they 
represent the first extensive study of the variation of the quantity of 
alkaloids in this important economic plant. 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
(129) 
Vol. I, No. 2 
Nov. 10, 1913 
G—3 
