Page:Popular Science Monthly Volume 44.djvu/225

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zation and scientific study of the laws of heredity and variation applied to plants?" The answer is, "Yes; there is no assignable limit to the capacity of our cultivated fruits, and of fruits still wild, to improve and develop new characteristics."

The second great task relates to the ceaseless struggle with the lower forms of animal and vegetable life which prey upon useful forms in immeasurable and innumerable hosts. Gophers and jack-rabbits are now only pests of minor importance in thickly settled orchard-districts, but the warfare of the horticulturist

PSM V44 D225 Fumigating tent for destroying scale in chino valley.jpg
Fumigating Tent. Hydrocyanic-acid gas process for destroying scale. Chino Valley.

with fungoid diseases and parasitic insects long ago passed its amusing stage. It is a serious business of importance to the whole human race, because whatever threatens the food supply threatens the life of man. The practical applications of skill and capital in the field of preventive and remedial agencies have been remarkable. Every successful Californian fruit-grower has now learned that he must as regularly treat his trees for scale and other inflictions as he must plow his land, thin the fruit, or gather the crop. At the spraying season in the fruit districts