The first point which strikes one about the mode of occurrence of the grasses on the face of the earth is their gregariousness. All meadows and many gardens in this country bear witness to the way in which the Gramineae, while living sociably among themselves, oust other plants. The same herd behaviour, coupled with exclusiveness, reappears among the bamboos. An American botanist, who has made a special study of the trees and shrubs of Japan, writes that in that country, “the forest-floor is covered, even high on the mountains, and in the extreme north, with a continuous, almost impenetrable, mass of dwarf Bamboos of several species, which makes traveling in the woods, except over long-beaten paths and up the beds of streams, practically impossible. These Bamboos which vary in height from three to six feet in different parts of the country…prevent the growth of nearly all other under-shrubs, except the most vigorous species”. The same writer attributes the climbing habit, which characterises so many Japanese plants, to this dense undergrowth of bamboos, which renders any other mode of life impracticable for relatively small species, if they are to keep a footing in the forests. The Gramineae are indeed formidable competitors in the struggle for space, not only because of their faculty for adopting a mass formation, but because they show an amazing tolerance about the external conditions of their lives.