290 RELATION OP FORESTS TO THE 



account which has been given of the geographical distribution of 

 forests in India, mention is made of forests near the bed of a river 

 frequently perishing, through that river changing its course ; all of 

 these are occurrences indirectly connected with the distribution of 

 the rainfiill. But while the trees perished, the herbage and the grass 

 flourished ; and it is the converse of this which we see in the growth 

 of the forest, where, it may be, lichen and moss, and fern and sedge, 

 and grass and herbage, had successively, alone or conjointly, held 

 for a time exclusive possession of the field. 



In further elucidation of this subject it may be mentioned that by 

 many it is held that, apart from all that has been alleged in regard 

 to evolution and development, there is a natural succession of plants 

 following each other in the occupation of the same ground, the homo- 

 logue of the natural succession of animals which have inhabited the 

 world, specified in Genesis as water animals and winged fowls, cattle 

 and creeping thing, and beast of the field and man, — and a struggle 

 for the possession of it between plants and possession by immigrants : 

 the homologue of man's replenishing the earth and colonising with 

 immigrant families lands previously peopled by other races And 

 both in connection with the natural succession and with the succes- 

 sion by immigration the distribution of rainfall has its function. 



It is frequently alleged that the order of natural succession is some- 

 thing like this : the germ of a lichen, falling upon a rock or stone, it 

 may be, being moistened by rain, or dew, or a little water lying there, 

 germinated, produced other germs, and died. Some generations did, 

 it may be, the same, produced other germs, and died ; subsequently, 

 it may be ages later, the germ of a moss, or of some other more 

 highy organised vegetable structure, fell there, and found in the 

 remains of decayed lichens a soil and the conditions favourable to its 

 germination and growth and reproductiun, and more favourable to its 

 continued reproduction than to that of the lichen, and ultimately it 

 obtained and maintained exclusive possession, it may have been for 

 ages, until some other germ or seed of some vegetable holding a still 

 hio-her position in the gradation of organic structures — a fern, it may 

 have been, a grass, a daisy, or some other herb, or all of these in 

 succession fell there, until at length on the accumulating soil there 

 appeared in succession, or in contemporaneous growth, a mass of 

 mixed and tangled vegetation, requiring only to be subdued by man 

 to make the soil composed of mineral constituents and decomposed 

 organic matter bring forth " fruits of increase" and " herbs meet for 

 them by whom it is dressed." 



