EFFECTS OF SELECTION ON ALKALOIDS IN BELLADONNA., 3 
| January. Late in April, when the plants from these seeds were about 
| 8 or 4 inches high, they were transplanted to the field. 
| In 1912 a second attempt was made to secure seeds from close- 
| pollinated flowers, and in order to insure fertilization the pollen was 
| transferred to the stigmas by hand before the flowers were inclosed. 
| The method of bagging the flower buds used in the previous year 
again proved ineffectual, since a species of aphis bred in the bags in 
| great numbers and destroyed the young plant tissues. Seeds were 
| obtained from a number of selected plants which had been inclosed in 
| cheesecloth cages, but even within those cages the aphides often 
| multiplied to such an extent as to injure the plant. The seeds from 
_ these plants were sown in flats in the greenhouse and the seedlings 
| therefrom transplanted to the field, the same as in 1911. 
FIRST-GENERATION PLANTS FROM CROSS-POLLINATED PARENTS. | 
The plants from the seed of the cross-pollinated selected individuals 
| in 1911 were transplanted to the field late in April. There were from 
| 6 to 15 individual plants from each parent. These plants made a 
fairly rapid growth and by midsummer were in full bloom, but the 
| growth they had made was not sufficient to make possible a picking 
from each individual plant. A collective sample was therefore se- 
cured from each set of individuals derived from the same parent. On 
| August 30, when the berries were partially ripe, the second picking 
_was made. In picking these samples care was taken to get leaves 
| from all the individuals, so that the results of the assay would indicate 
| as nearly as possible the average percentage of alkaloids in the leaves 
| of the individuals. Table II shows the results of the assays. 
| TasiEe II.—Alkaloids in the leaves of first-generation belladonna plants grown from cross- 
pollinated selected parents at Arlington, Va. 
Parent plant. Alkaloidal content (per cent). Parent plant. Alkaloidal content (per cent). 
Yield p Yield : 
= First Second First Second 
No. a oe picking. | picking. | AVet@se- No. rode: picking. | picking. | “Vt@8e- 
= Low...- 0. 524 0. 693 OF6097|*12ee oe. High.... 0. 650 0. 882 0. 766 
|) 3356S pce eres d 79 .518 AOR |e Wireteres 313) sae doze -617 1. 063 840 
| OF .4 A 
ae Medium . 640 . 859 S750) || Gweescene lees do.... . 805 1, 282 1. 043 
From Table II it is evident that these first-generation plants dis- 
_ played largely the characteristic of the parent plants as regards alka- 
‘loid production. Plants 7w and 6w merit special attention, their 
| leaves containing more than 1 per cent of alkaloids. 
The following season, 1913, these plants were large enough to fur- 
‘nish samples from each individual, and pickings were made at four 
| stages of growth during the season. The first picking was on May 6, 
before flowering; the second on May 23, when the plants were in full 
