115 



The Fmprovement of Medicinal Plants. 



By F. a. Millek. 



Certain suggestions were made before the last meeting of the Academy 

 for the possible improvement of valuable medicinal forms through the ap- 

 plication of breeding methods. .Some of tliese suggestions have been car- 

 ried out during the past summer u]Kin experimental pints of belladonna, 

 henbane, stramonium, digitalis and cannabis. The results, though oul.v ten- 

 tative, are extremely encouraging, aiul indicate a means of obtaining not 

 only greater yields of the lesnltiiig drugs. I)ut l)etter and more reliable 

 medicinal products. 



Belladdnna has sliown great uniformity in inorph(>logical characters, 

 but considerable variability in the ivercentage of alkaloids in selected 

 plants. In a comparatively small number this variation was found to be 

 over 50%, or from 0.n2% to O.ST'/f total alkoloids as found in the highest 

 and lowest yielding individuals. Much has been said concerning the varia- 

 tion in total alkaloids as influenced b.v various conditions. In fact some 

 experimental work has Iieen done up'ii the influence of such factors as food 

 elements, light and shade, soils, meteorology, etc., upon the production of 

 alkoloids and other active jirinciples. It now seems apparent, however, 

 that before such data can have any scientific bearing, or be utilized as a 

 means of following the influence of given factors, uniform strains of the 

 plants luider investigation must first be olttained. This apparent neces- 

 sity is due to the wide variations which have been found to exist between 

 the individuals of a given group which liave been grown under unirorm 

 conditions. 



A group of individual plants varying over n0'7f when grown under uni- 

 form ecological conditions cannot be expected to behave uniformly when 

 grown under varied conditions. Differences no greater than 50% have been 

 reported as being due to certain external influences as affecting all plants 

 upon a given area, while according to recent individual ])l:int investiga- 

 tions, such an area might i)roduce plants varying this nuich or more among 

 themselves, and representing at the same time any possible mixture with 

 reference to yield. It seems necessary, for this reason, to first obtain a 



