. Bulletin of the Department of Agriculture. Agriculture; Agriculture. EFFECTS OF SELECTION ON" ALKALOIDS IjST BELLADONNA. 11 for cross-pollination and to almost exclude the probability of close fertilization in individual flowers. However, the feeding habits of the principal pollinating insects (mostly night and day flying lepidoptera), which visit in turn many open blooms on the same plant, may tend after all to promote self or close pollination on a consider- able proportion of blooms on any given plant. If all the seeds in a single fruit should mature and produce plants with a hi
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. EFFECTS OF SELECTION ON" ALKALOIDS IjST BELLADONNA. 11 for cross-pollination and to almost exclude the probability of close fertilization in individual flowers. However, the feeding habits of the principal pollinating insects (mostly night and day flying lepidoptera), which visit in turn many open blooms on the same plant, may tend after all to promote self or close pollination on a consider- able proportion of blooms on any given plant. If all the seeds in a single fruit should mature and produce plants with a high alkaloidal content or any other transmissible ii 8°- \.70 . \.60- %.20\ £3(6) J(6) 7W(t>) 7W(a) 6W(6) 6W(a) Fig. 7.âDiagram showing the alkaloidal content of the leaves of first-generation belladonna plants from close-pollinated and cross-pollinated selected parents at two stages of growth during the second season, 1914. The percentages indicated represent the average of all the individuals from each parent plant: a, Plants from close-pollinated parents; 6, plants from cross-pollinated parents. feature of the seed parent, it does not necessarily follow that the pollen of another individual possessing this feature in a lesser degree might not have a reducing effect on the desired characteristic, as the seeds planted may easily be the result of actual close pollination between different blooms of the maternal plant or even of self- fertilization, of an individual bloom. It is but fair to suppose that a majority of the seeds of a given plant may thus be self-pollinated, notwithstanding nature's adapta- tion of the blooms for' crossing, unless it has been made apparent that belladonna blooms are not receptive to their own pollen or to that of flowers on the same plant, but must be fertilized by pollen produced by another individual. This conclusion has not been demonstrated by any controlled experiments that have come to mv knowledge. %so. ^.ao. \.60 §.S0t > 3J&a
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