HIR 



HIR 



tentacula, or horns, strongly annulated 

 and rugged upon the rings, the tail dilat- 

 ed. It inhabits the Atlantic ocean, and is 

 by the fishermen called the sea-leech. It 

 adheres to fish, and generally leaves a 

 black mark on the spot. 



The mouth of the leech is armed with 

 a sharp instrument, that makes three 

 wounds at once, and may be compared to 

 the body of the pump, and the tongue or 

 fleshy nipple to the sucker : by the work- 

 ing of this piece ofjmechanism, the blood 

 is made to rise up to the conduit which 

 conveys it to the animal's stomach, which 

 is a raembranaceous skin, divided into 

 twenty four-cells. The blood which is 

 sucked out is there preserved for several 

 months, almost without coagulating, and 

 proves a store of provision to the animal. 

 The nutritious parts, pure and already di- 

 gested by animals, have no call to be dis- 

 engaged from the heterogenous sub- 

 stances : nor indeed is there an anus dis- 

 coverable in the leech ; mere transpira- 

 tion seems to be all that it performs, the 

 matter fixing on the surface of its body, 

 and afterwards coming oflFin smallthreads. 

 Of this on experiment may be tried, by 

 putting a leech into oil, where it keeps 

 alive for several days : upon being taken 

 out and put into water, there appears to 

 loosen from its body, a kind of slough, 

 shaped like the creature's body. The or- 

 gan of respiration, though unascertained, 

 seems to be situated in the mouth; for if, 

 like an insect, it drew its breath through 

 vent-holes, it would not subsist in oil, as 

 by it they would be stopped up. 



It is only the first species that is used 

 in medicine, being applied to the skin in 

 order to draw off blood. With this view 

 they are employed to phlebotomise 

 young children. If the leech does not 

 fasten, a drop of sugared milk is put on 

 the spot it is wished to fix on, or a little 

 blood is drawn by means of a slight punc- 

 ture, after which it immediately settles. 

 The leech, when fixed, should be watch- 

 ed, lest it should find its way into the anus 

 when used for the hemorrhoids, or pene- 

 trate into the oesophagus, if employed to 

 draw the gums, as it would make, great 

 havoc in the stomach or intestines. In 

 such a case, the best and quickest reme- 

 dy is to swallow some salt ; which is the 

 method practised to make it loose its 

 hold when it sucks longer than was in- 

 tended. 



H. sanguisuga, horse leech : elongated, 

 olive brown, with an ochre-yellow mar- 

 ginal band : found in stagnant waters, 

 ditches, and ponds : from four to six 

 iuches long : body above dull olive-black, 



with an ochre margin on each side ; be- 

 neath paler, with sometimes a few black 

 spots ; tail thicker than the head. This 

 species sucks blood with great avidity, 

 and in large quantities. H. viridisj body 

 depressed, oblong, green, with a trans- 

 parent margin and pointed tail. This 

 species has been described by Dr. Shaw 

 in the " Transactions of the Linnxan So- 

 ciety :" it inhabits clear cold waters, is 

 about the eighth of an inch long, and, like 

 most of the genus, has a power of repro- 

 duction almost equal to that of the po- 

 lype ; for if the animal be divided in eve- 

 ry direction, the parts will become per- 

 fect animals, and may be again divided 

 and again reproduced. It is of a grass- 

 green colour, with a transparent border 

 all round. It has since been referred to 

 the genus Planaria. H. geometra, or 

 geometrical leech : body filiform, green- 

 ish, spotted with white; both ends dilata- 

 ble, and equally tenacious. It inhabits 

 fresh waters : moves as if measuring like 

 a compass, whence the name : it is found 

 on trout and other fish, after the spawn- 

 ing season. 



H1RUNDO, the sioalloio> in natural his- 

 tory, a genus of birds of the order Pas- 

 seres. Generic character : bill short, de- 

 pressed at the' base, small at the point, 

 and a little bending ; nostrils open ; 

 tongue short, broad and cleft; wings 

 long ; legs short ; tail, in general, forked. 

 These live almost perpetually in the air, 

 and perform in it every act of their na- 

 ture. They subsist upon the insects with 

 which that element abounds, and which 

 they catch on the wing with the most admi- 

 rable dexterity; and for this purpose they 

 are furnished with a most extraordinary 

 power of distending their jaws. The 

 service they perform to man by their in- 

 cessant assiduity in this work of destruc- 

 tion is not lightly to be appreciated, and 

 those who observe the crowded popula- 

 tion of the atmosphere through the beams 

 of a summer evening will easily be led to 

 believe, that, but for the interception t 

 incalculable myriads of insects by these 

 birds, the annoyance of man by these mi- 

 nute animals would be highly distressing, 

 and perhaps almost intolerable. The ce- 

 lerity of this tribe of birds is truly aston- 

 ishing, and that union of flexibility and 

 speed which they exhibit in pursuit of 

 their prey, or with which they elude the 

 grasp of their enemies, is highly remarka- 

 ble and interesting. Their manners are 

 eminently entertaining and social. They 

 fix their nests to the habitations of 

 man, and we not only extremely useful 

 in some respects, but perfectly inoffeit- 



