118 



strain of the form under investigation, tlao indivoduals of wliich will react 

 nnifoi-nily to c«>rtain external conditions. To investigate this point, plants 

 of kndwii allcaloidal yield are being propagated both from inbred seeds and 

 from vegetatiA'o cuttings. The progeny thus produced is being grown under 

 the sam-i conditions as the parent plants, as well as under widely dif- 

 ferent conditions. The alkaloidal yield of these plants will later be taken 

 as a means of detennining tlie results of the various treatments. 



The highest yielding individuals from all gnmps examined are imme- 

 diately selected as parent plants for possible high yielding strains. Tlie 

 propagation of these favorable individuals is continued throughout the year 

 by means of greenhouse and cold-frame accommodatinus, and are tested 

 as rapidly as sufficient material l)ecomes available. 



The production of henbane even uiwn a small exiierimeutal scale has 

 I roven extremely difficult. This difficulty is largely due to the ravag(» of 

 insects, although cultural difficulties with this plant are not uncommon. 

 It will uiit re]ir(P(hice itself from oiien field sowings and transjilants with 

 uncertainty. However, a small number of bieimial plants were grown 

 and found to test O.OsU^/, total alkaloids at the end of the first season's 

 growtli, wliile c(imm('rcial drug has only averaged 0.0(17% for tlie past year. 

 The rharmacop(eia re<iuires that this drug be collected from plants of 

 the second year's growtli. The above figures indicate that it may be en- 

 tii-ely unnecessary to m'ow this jilant through the second year to obtain a 

 high yield of alkaloids. The annual form was again observed, and though 

 no tests were made, an abundance of seed was obtained from which plant- 

 ings will be continued. The appearance of this annual form in many plant- 

 ings of henbane of supposed biennial origin lias led to much dispute. 

 Its investigation is necessai'y from tliis iK>iut of view as well as the possi- 

 bility for developing an annual form which would possess many cultural 

 advantages over the biennial. 



The selection of high yielding stramonium plants upon a basis of their 

 contained alkaloids has been continued through tAVO years. Averages as 

 obtained from the progeny of selected parent plants have shown a marked 

 increase over those from wild plants growing in the same locality. These 

 averages are O.CA(/c. 0.50%, 0.<iO% and O.G4% from Datura Stramonium L., 

 and 0.40%. 0.~A%, 0.62% and 0.nS;% from Datura tatula L.. as compared 

 with 0.2.'"!% from wild plants of Datura stramonium T.. and 0.42%r from 

 wild plants of Datura tatula L. 



Thirty-two forms of the genus Digitalis are under cultivation. These 



