|; 950 DIVISION Il ARTICULATED ANIMALS.— CLASS I. ANNELIDES. 
| panion. “It is especially in rich and well-manured soils that the Earth- 
| worm 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 of London. 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 pow- 
' erful agent in adding to the depth of the soil, and in covering compara- 
tively barren tracts with a superficial layer of wholesome mould. The 
| author’s attention was directed by Mr. Wedgwood, of Maer Hall, Stafford- 
shire, 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 showing the impossibility of this supposed operation, the author affirms 
| that the whole is due to the digestive process by which the common Earth- 
Worm is supported, since, on carefully examining between the blades of 
vrass 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 Earth-worms had covered a field, then 
| manured with marl, with a bed of earth, averaging thirteen inches in 
thickness.” 
Second Fatty. —This comprises the wrebristled or smooth animals. 
There are two genera, and numerous species, all which are aquatic. 
| | Iinupo. — The Leeches have an oblong body, sometimes depressed and 
wrinkled transversely, the mouth encircled by a lip, and the posterior 
extremity furnished with a flattened disk, both ends being adapted to fix 
upon bodies by a kind of suction, by means of which these animals move ; 
for, having fixed their anterior extremity, they draw the other up to it, and 
fix that, and then re-advance the first; besides which, they swim with 
facility. Several have a double series of pores underneath the body, which 
are the orifices of little internal pouches, considered by some naturalists as 
