398 
ANNELIDES. 
120 or more rings ; the bulge is towards its anterior third. Under the sixteenth ring are two pores, of which the 
use is unknown. It pierces the groiind in all directions, perforating it remarkably well, and subsists on roots, 
woody fibres, animal matter, &c. In the month of June it searches at night above ground for a mate. 
[It is especially in rich and well-manured soils that the Earthworm delights, particularly in gardens 
and meadows ; they are extremely sensitive to movements of the earth ; and anglers, knowing well their temerity 
in this respect, take advantage of it, in order to obtain a supply of these animals for baits, by introducing a spade 
or fork into the ground, and stirring the soil, when they soon appear on the surface. We are indebted to Charles 
Darwin, Esq., for a remarkable and interesting memoir on the utility of this animal, read before the Geological 
Society. The worm casts, which so much annoy the gardener by deforming his smooth-shaven lawns, are of no 
small importance to the agriculturist ; and this despised creature is not only of great service in loosening the 
earth, and rendering it permeable by air and water, but is also a most active and powerful agent in adding to the 
depth of the soil, and in covering comparatively barren tracts with a superficial layer of wholesome mould. The 
author’s attention was directed by Mr. Wedgwood, of Maer Hall, Staffordshire, to several fields, some of which 
had a few years before been covered with lime, and others with burnt marl and cinders, which substances in every 
case are now buried to the depth of some inches below the turf, just as if, as the farmers believe, the particles had 
worked themselves down. After shewing the impossibility of this supposed operation, the author affirms that 
the whole is due to the digestive process by which the common Earthworm is supported, since, on carefully 
examining between the blades of grass in the fields above-mentioned, he found that there was scarcely a space of 
two inches square without a little heap of the cylindrical castings of worms ; it being well known that worms 
swallow earthy matter, and that having separated the serviceable portion, they eject at the mouth of their burrows 
the remainder in little intestine-shaped heaps. Still more recently Mr. Darwin has noticed a more remarkable 
instance of this kind, in which, in the course of eighty years, the Earthworms had covered a field then manured 
with marl, with a bed of earth, averaging thirteen inches in thickness.] 
[Fig. 206, b, represents the anterior extremity of the Earthworm, to show the mouth, as well as the setae directed 
backwards upon the segments of the body, by means of which it is admirably enabled 
to work its way through the earth, their backward direction enabling it to retain its 
station as it protrudes its head further into the earth. Fig. e, represents one of its 
eggs, inclosing, as is sometimes the case, two young ; and fig. d represents the escape 
of the young worm from the egg, the anterior extremity of which is furnished with 
a peculiar valve-like structure ; these two figures are highly magnified,] 
Hypog<eon, Sav., have an additional single, or uneven, bristle upon the back of 
each ring. They are only known in America. 
MM. Audouin and M. Edwards likewise distinguish the Trophonius, which has 
four bundles of short silky bristles on each ring, and at the anterior extremity a 
great number of long and brilliant bristles, encircling the mouth. 
The Naides {Nais, Linn.),— 
Have the elongated body and the rings less marked than in the Earthworms. 
They live in holes which they perforate in mud at the bottom of water, 
and from which they protrude the anterior portion of the body, incessantly 
moving it. Some have black points upon the head, which have been 
regarded as eyes. They are small worms, the reproductive power of which 
is as astonishing as that of the Hydra or Polypus. Many species exist in our 
fresh waters. 
Some have very long bristles ; others (the Stylaria, Lamarck) a long protrusile 
trunk ; several {Proto, Oken) have small tentacles at the hind extremity, and there 
are others with very short bristles. 
To this genus may be approximated certain Annelides allied to the Earth- 
worms, which fabricate the tubes of clay, or debris, into which they retire. 
Such are the Tubifex of Lamarck, which, however, requires further examination. 
Climene, Sav., — 
Appears likewise to belong to this family. Their body is rather thick, 
with few rings, and bears, for the greater portion of its length, a range of 
strong bristles, and, a little higher up, a bundle of finer bristles on the dorsal aspect. The head has 
neither tentacles nor appendages ; posterior extremity truncated and rayed, and they also inhabit tubes. 
Fig;. 206.— Lumbricns terrestris. 
THE SECOND FAMILY OF THE ABRANCHIOUS ANNELIDES,— or. 
The Abranchia without Bristles,— 
Comprise two great genera, both of which are aquatic. 
