INTEODUCTION. 



about twice as many worms in gardens as in 

 corn-fields.* With respect to ''prairies 

 elevees," I do not know how it may be in 

 France, but nowhere in England have I seen 

 the ground so thickly covered with castings 

 as on commons, at a height of several hundred 

 feet above the sea. In woods again, if the loose 

 leaves in autumn are removed, the whole 

 surface will be found strewed with castings. 

 Dr. King, the superintendent of the Botanic 

 Garden in Calcutta, to whose kindness I am 

 indebted for many observations on earth- 

 worms, informs me that he found, near Nancy 

 in France, the bottom of the State forests 

 covered over many acres with a spongy layer, 

 composed of dead leaves and innumerable 

 worm-castings. He there heard the Professor 

 of " Amenagement des Forets " lecturing to 

 his pupils, and pointing out this case as a 

 "beautiful example of the natural cultiva- 

 "tion of the soil; for year after year the 

 " thrown-up castings cover the dead leaves ; 

 "the result being a rich humus of great 

 " thickness." 



* ' Zeitschrift fiir wissenschaft. Zoologie,' B. xxviii. 1877, 

 p. 361. 



