i88o 1882] EARTHWORMS 213 



magnificent, and I have worked at them for a day and Letter 547 

 a half. I find a very few well-rounded grains of brick in 

 the castings from over the gravel walk, and plenty over the 

 hole in the field, and over the Roman floor. 1 You have done 

 me the greatest possible service by making me more cautious 

 than I should otherwise have been viz., by sending me the 

 rubbish from the road itself ; in this rubbish I find very many 

 particles, rounded (I suppose) by having been crushed, angles 

 knocked off, and somewhat rolled about. But not a few of 

 the particles may have passed through the bodies of worms 

 during the years since the road was laid down. I still think 

 that the fragments are ground in the gizzards of worms, which 

 always contain bits of stone ; but I must try and get more 

 evidence. I have to-day started a pot with worms in very 

 fine soil, with sharp fragments of hard tiles laid on the surface, 

 and hope to see in the course of time whether any of those 

 become rounded. I do not think that more specimens from 

 Abinger would aid me. . . . 



To G. J. Romanes. Letter 548 



Down, March 7th. 



I was quite mistaken about the Gardeners* Chronicle ; 

 in my index there are only the few enclosed and quite 

 insignificant references having any relation to the minds of 

 animals. When I returned to my work, I found that I had 

 nearly completed my statement of facts about worms plugging 

 up their burrows with leaves, 2 etc., etc., so I waited until I had 

 naturally to draw up a few concluding remarks. I hope that 

 it will not bore you to read the few accompanying pages, 

 and in the middle you will find a few sentences with a sort 

 of definition of, or rather discussion on, intelligence. I am 



1 See The Formation of Vegetable Mould, 1881, pp. 178 et seq. The 

 Roman remains formed part of a villa discovered at Abinger, Surrey. 

 Excavations were carried out, under Lord Farrer's direction, in a field 

 adjoining the ground in which the Roman villa was first found, and 

 extended observations were made by Lord Farrer, which led Mr. Darwin 

 to conclude that a large part of the fine vegetable mould covering the 

 floor of the villa had been brought up from below by worms. 



2 Chapter II. of The Formation of Vegetable Mould through the 

 Action of Worms, 1881, contains a discussion on the intelligence shown 

 by worms in the manner of plugging up their burrows with leaves (pp. 78 

 et seq.']. 



