393 



AN?\ ELIDES. 



120 or more rini:;-g ; the bulp;e is towards its anterior tliird. Under the sixteenth rini;: are two pores, of vvhirli the 

 use is unknown. It pierces the <;roiuid in all directions, perforating" it remarkably well, and subsists on roots, 

 woody fibres, animal matter, &c. In the month of June it searches at nifi^'ht above ground for a mate. 



[It is especially in rich and well-manured soils that tbe Eartli^orm delights, particularly in gardens 

 and meadows ; they are exti-eniely 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 aniniais tor 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, Ksq., 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 Rgricultarist ; and this despised creature is not only of great service in loosening the 

 earth, and rerrdering it permeable by air and water, but is also a most active and powerful agent in achU.ng to the 

 depth of the soi!^ 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, Stafi^"ordiihire, 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 beloiv the turf, just as if, as the farmers believe, the particles had 

 woi'ked themselves down. After shewing the impossibibty of this supposed operation, tbe author affirms that 

 the whole is due to the digestive process by which the common Earthworm is supported, since, on carefully 

 examining l>etwcen the blades of grass in tbe 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, the\ eject at the mouth of their burrows 

 the remainder in little intestine-shaped heaps. Still njore 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 thirteer inches in thickness.] 

 [Fig. 206, h, represents the anterior extremity of the Earthworm, to show the mouth, as well as the seta? directed 

 bacliicards 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. <r, 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.] 



Hypogaon, 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 Tj-ophoum.^, 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 Kaides {Xais, Linn.), — ■ 

 Have the elongated body and the rings less marked than in the Eartliworms. 

 They live ia holes which they perforate in mud at the liottoui of \vater, 

 and from which they protrude the anterior portion of the hncly, incessantly 

 moving it. Some have black points upon the head, whicli have been 

 regarded as eyes. They are small worms, the reproductive power of which 

 is as astonishing as that of tbe Hy(h-a or Pul\pus. Many species exist in our 

 fresh waters. 



Some have very long bristles; others (ihe S/ijtarJa, Lamarck) a long protrusile 

 trrmk; several (Profo, Oken) have small tentacles at the bind extremity, and there 

 are others with very short bristles. 



To this genus maybe approximated certain Annelides allied to the Earth- 

 \\urnis, wliicli fabricate the tuhes of clay, or debris, into which they retire. 

 Such are tbe Titbifex of Lamarck, which, liowe^er, requires further examination. 

 Climexe, Sav., — 

 Appears likewise to belong to this family. Their body is rather thick, 

 Fi,;. 201..— Lumi.ricofi iern.stns. ^^.^^^ ^.^_^^^ riugs, aud bcars, fuT the greater poitiou of its length, a range of 

 strong bristles, and, a little higher up, a bundle of finer bristles on the dorsal aspect. Tbe head has 

 neither teiilacles nor appcnilagcs ; posterior extremity truncated and rayed, and they also inhabit tubes. 



TITE SECOND FAMILY OF THE ABRANCIIIOUS ANNELIDES —or, 

 The Abranchia without Bristles, — 

 Comprise two great genera, both of which are aquatic. 



