MANY people are inclined to brand the earthworm as a useless creature of disgusting, or even revolting, appearance and to regard it rather in the light of a nuisance. Their ranks are recruited mainly from those who have inherited, or acquired, a distaste for any animal, no matter how interesting or inoffensive, whose body is cold and somewhat clammy to the touch; and they do not trouble to inquire further into the matter. Yet the earthworm, like the toad, ‘ugly and venomous, bears yet a precious jewel in its head.’ It would go ill with mankind if earthworms were suddenly and completely exterminated. The agriculturalist and the horticulturalist can hardly claim or hope for a stauncher ally than is found in these lowly and insignificant creatures. Their normal method of feeding is to swallow large quantities of earth, digest the organic matter contained therein, and to void the indigestible matter as worm-casts. It has been calculated that there are some fifty thousand earthworms in an acre of arable land and that these bring to the surface more than twenty tons of soil annually in the form of casts. Much of this comes from the deeper layers of the soil since in dry weather the worms go down quite deep in search of moisture. This constant tunnelling and movement of the soil not only turns the ground over in the course of years, but allows it to be aerated and drained and, in general, to be exposed to the sweetening action of air and rain.
The regenerative powers of earthworms have become almost legendary and, as is usual with the growth of legends, strict accuracy is not always maintained. It is true that an earthworm cut in two becomes two individuals, the front half growing a new hinder end and the hinder part developing a new head. It is not true, however, that the swelling commonly seen near the front end of a worm is the scar formed from the healing of a wound, nor does it mark, as is often suggested, the spot where the two halves of a bisected worm have become joined together again. It is true that, under artificial conditions, the two parts of a cut worm can be made to graft together, but it is doubtful whether this ever happens
under natural circumstances. The so-called scai is better known as the ‘saddle ‘and is in reality a large glandular area which secretes a cocoon around the eggs as they are laid.