EFFECT OF THICK SOWING ON THE SEX OF DIOECIOUS PLANTS.

Hawera & Normanby Star, Volume I, Issue 62, 13 November 1880, Page 4 (Supplement)

EFFECT OF THICK SOWING ON THE SEX OF DIOECIOUS PLANTS.

At the meeting of German naturalists and physicians' at Badearßaden laßt, September, Professor Hoffman, of Giesson, as reported in the Berlin Monatsschrift, sought to show that seeds of unisexual plants, when thickly sown, result in a preponderance of males. Thus he found' that one hundred seeds of spinach, sown in a sixinch pot, yielded two males to every female, whereas the same sample of seed produced an equal number of males and females in the open ground where they had plenty of room. This observation would be important if of general application, and especially with hemp, but Haberland disputes it so far as this plant is concerned. According to Hoffman, sex does not reside in the seed, but depends on the conditions of germination. Unripe seeds of Lychdti vespertina, he found, gave a larger proportion of males than fully ripe seed. Seed of Mercurialis annua, artificially impregnated in early summer, gave more males than antumn J impregnated seed. Professor Prautl, of Aschaffenburg, remarked that crowded prothallia of feme produce a larger percentage of antherida, and scattered ones more archegonia. Professor Pfeffer, of Tubingen, stated that he had observed a similar phenomena in the case of equisetum.