HBtcttanarj) of ffmmatcfr jflature. 371 



They should not be disturbed whilst suck- 

 in<r nor the patient be exposed to too great 

 warmth, or they will fall off ; this they 

 should always be permitted to do ot their : 

 own accord. When the Leech has dropped 

 off, it should be seized by the tail, and drawn 

 between the finger and thumb, so as to cause it : 

 to disgorge most of the blood; or this may be i 

 effected by putting it in a week solution of 

 common salt. It should then be placed in 

 many successive fresh waters, and if not 

 injured, it may be used again at a future 



The increasing scarcity of Leeches," as 

 is remarked by Mr. Broderip, " renders their 

 preservation and propagation objects of pri- 

 mary importance. The death of a vast 

 number of Leeches is occasioned by errors 

 in the method of keeping them. Though 

 aquatic animals, it is not enough that they 

 be supplied with water They breathe by 

 their entire surface, and are accustomed to 

 change their skins every four or five days. 

 Their body is covered, like that of all ani- 

 mals and plants which inhabit the water, by 

 a shiny or mucilaginous fluid, which not 

 only enables them to glide through the water, 

 but keeps an aerial stratum in close contact 

 with their respiring surface. AVhen present 

 n a limited degree, this mucous secretion is 

 .lighly serviceable to them; in excess it is de- 

 structive. It is impossible for them to dimi- 

 nish it when it has accumulated, or to denude 

 themselves entirely of their old skin, iu 

 water only. They must have some resisting 

 body to creep over or through in order to 

 accomplish this object." The most effectual 

 method of preserving them appears to be 

 that recommended by Fee ; which is as 

 follows : " Into a marble or stone trough a 

 layer of seven inches of a mixture of moss, 

 turf, and charcoal of wood is to be put, and 

 some small pebbles placed above it ; at one 

 extremity of the trough, and midway be- 

 tween the bottom and the top, place a thin 

 plate of marble pierced with numerous small 

 holes, upon which there should rest a stratum 

 of moss, or portions of the equisetum palustre, 

 or horse-tail, firmly compressed by a stratum 

 of pebbles. The trough to be replenished 

 with water only so high that the moss and 

 pebbles should be but slightly moistened. 

 A cloth is to be kept over the mouth of the 

 trough. This is imitating as near as pos- 

 sible their natural condition, and the char- 

 coal not only aids in keeping the water 

 sweet, but appears to prevent the Leeches 

 being attacked by parasitic animals, to which 

 they are very liable. The water should be 

 changed about once a week, and more fre 

 quently in warm weather." To judge of 

 the vast numbers of Leeches that are re- 

 quired for medical uses, and of the great 

 importance it is to ascertain the best method 

 of preserving them, it is only necessary to 

 state, that four only of the principal dealers 

 in London import between seven and eight 



millions annually I 



The HORSE-LEECH. (Hirudo sanyuisuga, 

 Linn. ) The body of this species is depressed 

 and in the bottom of the mouth there are 

 certain sharp tubercles. The mouth anc 



tail are slender ; the body is pretty thick ; 

 the belly is of a yellowish green colour, and 

 the back is dusky. It is very common in 

 shallow pools and stagnant waters. 



The MECHANICAL LEECH. (Hirudo geo- 

 metra, Linn.) This species is found ad- 

 hering to the trout and some other fishes 

 after the spawning season. Its motions are 

 performed by a particular expansion of the 

 head and tail, as if measuring like a com- 

 pass ; and hence it receives its name. The 

 .rody is greenish, spotted with white ; and 

 >pth ends are dilatable and equally tena- 

 cious. 



The TUBERCULATED LEECH. (Ponto- 

 ella muricata.) A marine species, which 

 adheres strongly to fish, and leaves a black 

 mpression on the place. The body, which 

 s taper and rounded at the greater extre- 

 ity, is furnished with two small horns, 

 strongly annulated, and tuberculated on the 

 rings ; and the tail is dilatable. 



LEIPO A. A genus of Gallinaceous birds, 

 the only known species of which is 



LEIPOA OCELLATA. The " Native Phea- 

 sant " of the colonists of Western Australia ; 

 which in its habits is very like the domestic 

 'owl. It deposits its eggs in a mound of 

 mnd, about three feet high, the inside being 

 lined with layers of dried leaves, grasses, &c. 



The bird never sits on the eggs, but leaves 

 them to be hatched by the heat of the sun's 

 rays. The natives are very fond of the eggs, 

 and rob the mounds twice or thrice in a 

 season. These mounds resemble ant-hills ; 

 and, indeed, ants often abound in them. 

 Captain Grey observes that the nests are at 

 least nine feet in diameter and three feet 

 high. By the natives this bird is named 

 Ngowoo. 



LEMMING. (Georychus lemmus.') There 

 are several species of this animal, varying in 

 size and colour according to the regions they 

 inhabit. They are found in Norway, Lap- 

 land, Siberia, and the northern parts of 

 America ; those of Norway being nearly the 

 size of a water rat, and of a tawny colour, 

 variegated with black, the sides of the head 

 and the under parts being white ; while 

 those of Lapland and Siberia are scarcely 

 larger than a field mouse, and much less 

 distinctly marked. The head of the Lem- 

 ming is large, short, thick, and well furred ; 

 the eyes and ears small ; the body thick ; 

 and the limbs short and stout, especially the 



