6 BULLETIN 306. U. S. DEPARTMENT OF AGRICULTURE. 
the stage before flowering and the stages when the berries are 
ripe. In another season, however, the same plants were found to 
be richer in alkaloids at the second and fourth stages. In the 
present investigation we find the greatest percentage of alkaloids 
at a stage of growth which corresponds to the fourth stage in the 
3220 previous investigation. It seems, then, fur- 
See ther established that the greatest concentra- 
y .70 ° . ° . 
S 60 tion of alkaloids is at the period when the 
5 04 berries are mostly ripe and the leaves small 
8 al and sparse. 
RK 
= .20 
S 108 COMPARISON OF FIRST-GENERATION PLANTS 
to FROM CROSS-POLLINATED AND CLOSE-POL= 
LINATED PARENTS. 
Fig. 4.—Diagram showing the 
average alkaloidal content of Krom the parent plants, 6w and 7w, which 
all the individual belladonna = : - - 
plants from each parent for yielded the progeny described in the foregoing 
the season, second year, 1913. pages, seeds were obtained in 1912 through 
both cross and close pollination and planted for purposes of compari-— 
son. Plants 12, 13, 3, and 34 were dead; therefore no seeds could be 
secured from them. In their stead, seeds were taken from plants 46 
and 23, as these were examples of low alkaloid-yielding plants. The 
seeds were sown in the greenhouse and the seedlings transplanted to 
the field early in May, 1913. Owing to the hot weather and severe 
drought the plants made only a fair growth, and only two pickings 
were secured, the first on August 19, when the plants were in the 
flowering stage, and the second on September 23, when the berries 
were in various stages of ripeness. Table IV shows the percentage | 
of alkaloids in the leaves of the individuals from each selected parent. 
Tasie 1V.—Alkaloids in the leaves of first-generation belladonna plants from close polli- 
nation and cross-pollination of selected parents at two stages of growth at Arlington, 
Va., during the first season, 1913. 
Alkaloidal content (per cent). | Alkaloidal content (per cent). 
| 
Lot and number. Hirst Seoul | Lot and number. | First Sacodd 
stage, stage, | Average. | stage, stage, | Average. 
Aug. 19. | Sept. 23. | Aug. 19. | Sept. 23. 
Lot 6w, close polli- | Lot 6w, close polli- | 
nated: nated—Contd. 
Pee Hee q . <8 0.514 0. 430 0.472 10S 23-02 SS 0. 745 | 0. 658 0. 702 
2 Se 687 594 640 iT ea ee S| ee ee ee 
ee ee eo 421 504 . 463 1 ee ee . 741 705 723 
Ae Sey SEE as 834 886 . 860 1S Se. ee . 687 613 
Se. ae 773 736 755 1 Eh ena RR 2 ge . 767 750 759 
Cee eae oe 731 724 728 1D ee ee oe . 658 760 719 
[Reg ee A 689 745 717 1G teve Estates . 703 722 713 
ee ae 735 633 684 Migr: Ao | ee 786 741 764 
Naas She eae 696 669 683 || 1S 45 o25 ese 865 515 690 
