250 THE JOURNAL OF INDIAN BOTANY.
case in which a xerophytic retrogression might hasten the ultimate appearance of climax mesophytic conditions.
In the Bauhinia forest, Euphorbia Boyleana, on account of its succulence, resists fire better than any other plant of its size. But here, as in the pine and oak forests, practically all the shrubs and younger trees succumbed. The course of plant succession is every- where greatly affected by burning.
The cutting of timber, likewise a retrogression to the xerophytic, might hasten also the ultimate coming of the mesophytic oak forest, because the oak coppices freely, the pine not at all. The oncoming forest is usually preceded by a jungle of Rosaceous shrubs (Prinsepia utilis, Crataegus crenulata, Pyrus pashia, Eosa moschata, Rubus ellipticus) with which are mingled Berberis asiatica and Rhamnus virgatus. The duration of the shrubby stage depends largely on the abundance of the sclerophyllous trees left to coppice, for they are good coppicers. It depends furthermore on the extent to which cutting continues. There is no tree in the region more sought after than the oak. Used for fuel, for fertilizing the land, for thatching, for tanning and for cattle fodder, the wonder is that it maintains a foot-hold at all. The Bauhinias also are much cut, but readily spring up after cutting.
Grazing does not, of course, greatly affect the large trees. It effectually keeps down the seedlings of most trees and gives rise to a grassy forest. When persisted in, as the old trees die, a grassland results which must go through the xerophytic stages before the mesophytic forest can be renewed.
Cultivation is more serious than mere cutting because the stumps are grubbed out and the chance for coppicing removed. Preparation for cultivation involves contouring and terracing of the land. The place most suited for the entrance of vegetation is the terrace edge. Its fir3t conspicuous flora is the aggregation of rosaceous herbs men- tioned above with such others as Berberis, Rhamnus and Clematis. These may be followed by Euphorbia and Sapium which lead to the Bauhinia or the oak, more commonly the latter in the Sat Tal alti- tude. In Sat Tal valley on a flat that was cultivated over fifty years ago the large oaks which make up the bulk of the forest can be re- cognized as growing on old terrace edges.
Hydrarch Successions.
In this region are three classes of habitats with more than the normal amount of water, — streams of the wet season, lakes with steep sloping shores, such as the large lakes which give the name to Sat
