HARD WI CKE'S SCIENCE- G OS SIP. 



i55 



granular and mammillated appearance, somewhat re- 

 sembling mouse-dirt. It does not seem to be thrown 

 out of the hole mixed with the rest of the earth, but 

 it is deposited separately, often in considerable 

 quantity. If you crumble it when dry, you will find 

 it full of vegetable fibre, which has the appearance of 

 undigested moss, or small blades of dried grass, 

 curiously rolled up in rather hard little pellets, which 

 do not easily crumble with the rest of the earthy 

 excreta. It is clear, therefore, that the dirt of the 

 lob -worm is part vegetable, though the greater part 

 of it is simply earth. If the excreta are dissolved in 

 water, the vegetable debris is still more easily col- 

 lected on the top of the muddy sediment. It is not 

 surprising, from the nature of their food, that the 

 richest earth is generally most full of worms. They 

 are scarcely ever found in digging in sand or gravel, 

 and this is the reason why you so rarely meet with 

 mole-hills in sandy or pebbly soil ; viz., because these 

 clever little creatures find out that worms are not lo 

 be had there for their trouble in boring. How the 

 worm ejects these little pellets on the outside it is 

 perhaps impossible to say. The head is always pro- 

 truded first from the hole ; can it be that the pellets, 

 after being discharged, are conveyed to the surface 

 by some special process ? Or does the worm emerge 

 entirely from its hole during the night ? The excreta, 

 however, are never found apart from the worm-cast 

 covering the hole. 



I enclosed three large worms in a flower-pot of 

 moist earth, covering it so as to prevent their escape, 

 and occasionally sprinkling a little water on the surface. 

 I found, as I had expected, the next morning that a 

 hole had been bored, opening to the surface, and the 

 bits of earth were thrown out, but not a particle 

 of the excreta. I then placed some leaves, with 

 bits of stick and string, on the surface of the pot, 

 in order to see if they would be used as a plug for 

 the hole. 



I was desirous also to ascertain if the worm came 

 to the surface to feed, or if it in any way disturbed or 

 fed on the leaves, the positions of which and their 

 condition I took note of. I found that the bits of 

 string and the leaves had been all moved, and some 

 of them drawn into the aperture of holes they had 

 opened against the sides of the pot ; also that the 

 leaves were in part nibbled away, if one may use 

 such a term of a creature which has only some power 

 of sucking up or sucking off. It seems certain then 

 that worms swallow both earth (rich earth in pre- 

 ference to poor or sandy earth) and also fibrous 

 vegetable matter. 



Every effect that the worm leaves visible on the 

 surface seems done at a time when its enemies, the 

 birds, are not abroad. How a blind creature can tell 

 night from day seems surprising ; possibly the warmth 

 of the sun, or the dew at night may serve it for this 

 end. By keeping one or two worms in a flower-pot, 

 I once or twice found one partly exposed. It was 



! passing, by peculiar jerks made, with intervals of rest , 

 from one hole into another. From this I suspected 

 that, as in a rabbit-warren, the same creature has 

 several holes communicating with each other under 

 ground. 



To ascertain this, after keeping the worms fo 

 some time in a flower-pot, I let them escape, and by 

 drying the earth I was able to dissect it so as to 

 expose all the galleries and passages. I found these 

 very numerous, and towards the bottom of the pot 

 containing portions of leaves which had been drawn 

 down for food. Grains of wheat and other seeds had 

 been carried down to the bottom, and it seemed to 

 me that the worms had fed on the tangled roots which 

 these seeds had sent out through the whole thickness 

 of the earth. The excreta in some cases were adhering 

 to the sides of the pot. I think they must have some 

 way of conveying it or pushing it out of their holes, 

 as birds are said to eject the dirt of the young nest- 

 lings. I think, also, that it is got rid of as soon 

 as deposited. For, though worms are very shy of 

 making themselves visible by day, it is common to 

 find worm-casts so moist and fresh that they have 

 evidently just been thrown up. This is the case with 

 mole-heaps ; but I never saw, and I never met with 

 any one who could say that he had seen, the earth 

 actually being thrown up. The mole, like the worm, 

 is evidently very sensitive to the tread of a foot. 

 Both remain quiet when they feel the vibration of 

 the ground. 



Worms by no means invariably draw into then- 

 holes leaves or bits of sticks, or cover them over with 

 pebbles. The reason of their doing so at all is there- 

 fore the more obscure, since it is not a necessity. Very 

 often the hole is marked only by the little heaps of 

 earthy excreta, and however carefully you remove 

 these, you will find the hole itself is completely 

 stopped. They nibble off the ends first, and then 

 pull the remainder down lower, till little more than 

 the stalk and mid-rib is left. And a little observa- 

 tion will show that the leaves have really been 

 devoured, and have not rotted away in the moist 

 earth. This fact I ascertained to a positive certainty 

 by repeated supplies of diy leaves put into the flower- 

 pot, the whole being clean eaten up except short por- 

 tions of the stalks. It seems then that a very large 

 part of the decaying vegetable matter in gardens is 

 consumed by the numerous lob-worms, for they are 

 greedy eaters, though they seem to do no harm to 

 growing plants, even if they do eat some of the fibrous 

 roots. In this respect the worm resembles the mole 

 and the dung-beetle, which never leave the hole to the 

 upper surface open to the air, as most of the burrow- 

 ing animals do. 



Nevertheless, it is certain that worms do feed on 

 leaves or bits of stick drawn into their holes. My 

 grass-plot in late autumn quite bristled with the tufts 

 of fallen willow-leaves (the weeping willow), but in a 

 few weeks they had vanished, entirely consumed by 



