INTRODUCTION. 3 



I became interested in them, and -wished to 

 learn how far they acted consciously, and how 

 much mental power they displayed. I was 

 the more desirous to learn something on this 

 head, as few observations of this kind have 

 been made, as far as I know, on animals so 

 low in the scale of organization and so 

 poorly provided with sense-organs, as are 

 earth-worms. _J 



In the year 1837, a short paper was read 

 by me before the Greological Society of 

 London,* " On the Formation of Mould," in 

 which it was shown that small fragments of 

 burnt marl, cinders, &c., which had been 

 thickly strewed over the surface of several 

 meadows, were found after a few years lying 

 at the depth of some inches beneath the turf, 

 but still forming a layer. This apparent 

 sinking of superficial bodies is due, as 

 was first suggested to me by Mr. Wedgwood 

 of Maer Hall in Stafi'ordshire, to the large 

 quantity of fine earth continually brought 

 up to the surface by worms in the form of 

 castings. These ■eastings are sooner or later 



• ' Transactions Geolog. Soc' vol. v. p. 505. Bead Novem- 

 ber 1, 1837. 



