172 CHARLES DARWIH 



had found out in very truth that many a little makes a 

 mickle, that the infinitely small, infinitely repeated, 

 may become in process of infinite years infinitely im- 

 portant. So he set himself to work, with characteristic 

 contempt of time, to weigh and measure worms and 

 worm-castings. 



He began by keeping tame earthworms in flower- 

 pots in his own house, counting the number of worms 

 and burrows in certain measured spaces of pasture or 

 garden, and starting his long and slow experiment in 

 his field at Down already alluded to. He tried issues 

 on their senses, on their instincts, on their emotions, 

 on their intelligence ; he watched them darting wildly 

 like rabbits into their holes when alarmed from without, 

 overcoming engineering difficulties in dragging down 

 oddly-shaped or unfamiliar leaves, and protecting the 

 open mouths of their tunnels from intruders with a little 

 defensive military glacis of rounded pebbles. He found 

 that more than 53,000 worms on an average inhabit 

 every acre of garden land, and that a single casting 

 sometimes weighs as much as three ounces avoirdupois. 

 Ten tons of soil per acre pass annually through their 

 bodies, and mould is thrown up by them at an average 

 rate of 22 inches in a century. Careful observations 

 on the stones of Stonehenge; on the tiled floors of 

 buried buildings; on Roman ruins at Silchester and 

 Wroxeter, and on his own meadows and pastures at 

 Down, finally enabled the cautious experimenter to 

 prove conclusively the truth of his thesis, and to present 

 to the world the despised earthworm in a new character, 

 as the friend of man and of agriculture, the producer 

 and maintainer of the vegetable mould on our hills or 



