18 Practical Farming 



high mountains of India earthworms were found, and in 

 Ceylon, Professor King foimd a worm two feet long and a 

 half inch in diameter. As the worm goes deep in the 

 earth to hibernate during the winter season in the tem- 

 perate zones and in the dry season of the tropics, the 

 amount of material they bring to the surface has a great 

 influence on the formation and nature of the surface of 

 the soil. 



Darwin gives a number of cases where ashes and cinders 

 were spread on the surface and after some years were 

 deeply covered by the earthy matter brought up by the 

 worms from below, till a new soil was formed solely 

 by the worms. At an abandoned limekiln in England 

 several large sandstone pieces were left lying on a hard 

 rubbish of broken bricks and mortar. Thirty-five years 

 later found the stones covered with a deep layer of soil and 

 turf. He had one of the stones removed by men with 

 crowbars, and found that it still rested on the broken bricks 

 and mortar, and showed no signs of having sunk, but the 

 soil and turf had accumulated around it, sloping up to 

 the top in a crater-like form, and the fine vegetable mold 

 around it evidently consisted of the castings of worms, 

 some of which were quite recent. Measuring the rate at 

 which the stone had actually settled, he estimated that it 

 would have taken two hundred and forty-seven years for 

 it to settle so as to bring its surface even with the surface 

 of the earth. From this and other investigations he be- 

 came satisfied that the accumulation of soil through the 

 ejections of earthworms had a very important influence 

 on the increase of the upper soil. Darwin estimated that 

 the number of earthworms in an acre of land was about 



