The History of Things 59 



mitigate floods, and keep the springs welling and 

 the streams flowing in days of drought. Many 

 little plants smooth away the wrinkles on the 

 earth's their mother's face, and adorn her with 

 jewels. Others have caught and stored the sun- 

 shine, hidden its power in strange guise in the 

 earth, and our hearths with their smouldering 

 peat or glowing coal are warmed by the sunlight 

 of the summers of thousands or millions of years 

 ago. The grass, which began to grow in com- 

 paratively modern (i. e. y Tertiary) times, has made 

 the earth a fit home for flocks and herds, and pro- 

 tects it like a garment; the forests affect the rain- 

 fall and temper the climate, besides sheltering 

 multitudes of living things, to many of whom 

 every blow of the axe is a death-knell. In fact, 

 no plant, from bacterium to oak-tree, either lives 

 or dies to itself, or is without its influence, direct 

 or indirect, upon the earth. In arguing from the 

 present rates of earth-weathering to those in past 

 ages, geologists have not perhaps taken sufficient 

 account of the degree in which the hand of life, 

 especially in more modern times, has modified the 

 extra-animate cosmic operations. 



Similarly, as regards animals, the influence of 

 the hand upon life upon the earth is manifold. 

 On the one hand we see destructive agencies 

 the boring sponges and worms reduce the shells 

 to sand, the Pholads and other larger borers help to 



