CALIFORNIA FOR THE BOTANIST 273
other activities. If an effort were made, I have no doubt that a very considerable list might be made of plants known to bloom and to fruit only scantily and rarely elsewhere which fruit regularly under the stimulus of the richer and more abundant light which penetrates the dryer atmosphere of the Pacific coast. Liverworts and mosses, "shade- loving" here as elsewhere, fruit abundantly and regularly, but it should be stated that their spores do not always reach perfection because there may not be time enough between the cessation of the rains and the beginning of the really dry season for them to mature fully. But, given the necessary minimum of water in soil and air, plants will fruit, crops will come, the more abundantly the more light of suitable composition they receive. And we shall presently see that the rays of the upper half of the spectrum, the violet and the ultra-violet, the ones most absorbed by water and water vapor, whether visible or not, are the ones most stimu- lating to bloom and fruit. Soil fertility, light fertility, and water — these three — and the greatest of these is water.
��VOL. LXXXVI. — 19.