=Weeds under Cultivation.=--For several years past the botanical department of Michigan Agricultural College has maintained a "weed garden," and has grown a hundred or more species of the most troublesome weeds in plots. Some curious results from the experiments are recorded by Prof. W. J. Beal in a paper read at the meeting, 1897, of the Society for the Promotion of Agricultural Science. The most vigorous and aggressive weeds seem to take on under cultivation the weakness and capriciousness of delicate cultivated plants. "It is very instructive," Professor Beal says, "to note how much better many of these plants thrive when they get away from the spot where they have been confined for from two to several years. Seedlings of Jamestown weed were larger in the plantain bed than in their own. After three years the plantain nearly ran out and _Amaranthus albus_ entirely disappeared. One species of pigweed grew finely for two years, but afterward made a small display; and another variety did not seem very persistent for a plant that ranked among the weeds, but shied off from its home ground 'as if searching for fresh fields.' Barnyard grass (_Panicum crusgalli_) behaved like pigweed, and 'needed considerable attention.' The little round-leaved mallow, which roots deeply about rubbish piles in mellow soil, was grown of respectable proportions in the garden with considerable difficulty, and with no more ease in the bottom lands of other parts of the botanic garden. Considerable pains is required every year to keep on hand even fairly well-grown specimens of mullein. Knotgrass, which thrives with abuse and seems to enjoy trampling by feet, was grown with difficulty in the plots. 'Insects prey upon it; rust causes it to dwindle and disappear.' 'Motherwort grows rank four feet high near the barnyard fence, and the flowers are covered with bees, but when kept several years in the same bed it goes off into the sulks as though neglected.' Shepherd's purse is often disturbed by a parasitic fungus, and it is difficult to grow nice plants long in the same place. Cocklebur, if found long in the same spot, is troubled sadly with a mildew, and more recently also with a rust."