EFFECTS OF SELECTION ON ALKALOIDS IN BELLADONNA, 5 
A careful study of Table III reveals the fact that the individual 
first-generation plants possess in large measure the same alkaloid- 
| 220 
| Ro 
| Yeo reall 
| S ae AVERAGE a aa 
hoc SS |} ——— et 
ia: hii 1. ee 
| xe 3 sia | ee 
0 a | nga 
Ss 1 am) ee sey aT i 
Son os 
Cw 
Ue 
F 
| Fic. 1.—Diagram showing the alkaloidal content of the leaves of first-generation belladonna plants from 
| cross-pollinated parents at two stages of growth during the first season, 1912. The percentages indicated 
represent the average of all the individuals from each parent plant. ; 
producing characteristic as the parent plant. Plant 6w, the richest 
of the original 59 individual plants under observation for two years, 
yielded from cross-pollination first-generation 
plants which were distinctly rich in the first 
| season and again in the second season. Fur- 
' thermore, the plants of the first generation 
from the cross-pollinated individuals selected 
_ from the original list for low alkaloidal content 
have shown a decidedly low percentage of 
alkaloids during each of the two seasons of 
‘growth. Figures 1 to 4 show graphically the 
average percentage of alkaloids in the leaves : 
of all the first-generation plants from each (ee ee ast conteat of 
parent at each of the pickings in 1912 and __ allthe individual belladonna 
1913. Besides showing at a glance what has feos net your 1012. 
already been said regarding the plants which 
are rich or poor in alkaloids, figure 1 also shows an interesting con- 
dition with regard to the relative richness of the plants at the 
PERCENTAGE OF ALAALOIOS 
BS AVERAGE. one 
ENTAGE OF ALHALOIOS 
FERC! 
Fic. 3.—Diagram showing the alkaloidal content of the leaves of first-generation belladonna plants from 
cross-pollinated selected parents at four stages of growth during the first season. The percentages 
indicated represent the average of all the individuals from each parent plant. 
| various stages of growth. In the previous investigation! the plants 
| were richest in alkaloids at the first and fourth stages; that is, 
1Sievers, A. F. Op. cit. 
