quainted, it would therefore seem, with the device of the shepherds in Hungary, who grease their clothes with hog's lard to deter the fleas, nor with the old English preventive:

"While wormwood hath seed, get a handful or twaine

To save against March to make flea refraine:
Where chamber is swept and wormwood is strown,
No flea for his life dare abide to be known *."

Linnæus was in error in stating that the domestic cat (Felis maniculatus, TEMMINCK?) is not infested with fleas; for in kittens in particular they abound as numerously as upon dogs t.

Fleas, it may be worth remarking, are not all of one species, those which infest animals and birds differing in many particulars from the common bed flea (Puler irritans), and as many as twelve distinct sorts have been found in Britain alone ‡. The most annoying species, however, is fortunately not indigenous, being a native of the tropical latitudes, and variously named in the West Indies, chigoe, jigger, nigua, tungua, and pique (Pulex penetrans, LINN.)

Chigoe (Pulex penetrans).

According to Stedman, this " is a kind of small sandflea, which gets in between the skin and the flesh without being felt, and generally under the nails of the toes; where, while it feeds, it keeps growing till it *Tusser, Points of Goode Husbandry. † J. R.

Insect Transformations, p. 393.

becomes of the size of a pea, causing no further pain than a disagreeable itching. In process of time its operation appears in the form of a small bladder, in which are deposited thousands of eggs, or nits, and which, if it breaks, produce so many young chigoes, which in course of time create running ulcers, often of very dangerous consequence to the patient; so much so indeed, that I knew a soldier, the soles of whose feet were obliged to be cut away before he could recover: and some men have lost their limbs by amputation, nay, even their lives, by having neglected, in time, to root out these abominable vermin. The moment, therefore, that a redness and itching more than usual are perceived, it is time to extract the chigoe that occasions them. This is done with a sharp-pointed needle, taking care not to occasion unnecessary pain, and to prevent the chigoe from breaking in the wound. Tobacco ashes are put into the orifice, by which in a little time the sore is perfectly healed *." Old Ligon tells us that in this way he had ten chigoes taken out of his feet in a morning "by the most unfortunate Yarico †," whose tragical story is so well known from the popular drama. Walton mentions that a Capuchin friar, in order to study the history of the chigoe, permitted a colony of them to establish themselves in his feet: but before he could accomplish his object, his foot mortified and had to be amputated. No wonder that Cardan calls the insect "a very shrewd plague §."

Another troublesome sort of insects, less dangerous perhaps, though equally pertinacious, and more widely diffused than the chigoe, is the family of gnats (Culicida). Even these, however, sometimes produce formidable consequences; for M. Réaumur

*Stedman's Surinam; and Swartz, Swedish Trans., ix. 40. History of Barbadoes, p. 65. Walton's Hispaniola.

§ Subtilia. lib. ix.

66

says, "I have seen in marshy districts on the sea coast, individuals whose arms and legs were rendered shocking with the reiterated bites of gnats, and some of them so bad, that it was doubtful whether they could be cured without amputating the limb*" He adds, that if we will exert a little patient attention, we shall be compelled to admire the very instrument with which the insect wounds us. The elder Pliny becomes more than usually eloquent upon the structure of this insect. "In these so little bodies," he says,nay, points or specks, rather than bodies indeed,-how can one comprehend the reason, the power, and the inexplicable perfection that Nature hath therein shewed? How hath she bestowed all the five senses in a gnat? and yet some there be lesse creatures than they. But where, I say, hath she made the seat of the eyes to see before it? Where hath she set and disposed the taste? Where hath she placed and inserted the organ of smelling? and above all, where hath she disposed that dreadful and terrible noise that it maketh—that wonderful great sound, as I may call it, in proportion to so little a body? Can there be devised a thing more finely and cunningly wrought than the wings set to her body? Mark, what long shanked legs above ordinary, she hath given unto them. See, how she hath set that hungry hollow concavitie instead of a belly and hath made the same so greedie and thirstie after blood, and man's especially. Come to the weapon that it hath to pricke, pierce, and enter through the skinne; how artificially hath she pointed and sharpened it! and being so little as it is, for the fineness thereof can hardly be seen, yet as if it were of bignesse and capacity answerable, framed it, she hath, most cunningly for a two-fold use, to wit, most sharpe pointed to pricke and enter, and withall, hol*Mém. iv. 573.

:

S

low like a pipe to sucke in and convey the blood through it*"*

It is not a little singular that notwithstanding the early attention which was thus given to the sucker of the gnat, authors are by no means agreed as to its structure; and even a recent author of talent, M. Robineau Desvoidy †, has rather added to former errors than contributed to expunge them. The most accurate details and figures are those of Réaumur and Roffredi, which we shall chiefly follow. To the naked eye, the sucker of the gnat appears like a needle finer than a hair, solid and pointed; but the microscope shows that what appeared so simple, is really compound and complicated. It consists, according to Leeuwenhoeck of four pieces; Swammerdam found six, including the lip; but Réaumur says there are only five. It may be that their observations were made upon different species, or upon individuals which had sustained accidental mutilation. Swammerdam, indeed, mentions that he often observed in dead gnats the suckers broken off from their case. This case or sheath is divided in its whole length, enclosing an apparatus of five piercers or lancets (Scalpella), with which it cuts into the skin. "After a gnat," says Réaumur, "had done me the honour of settling on my hand, I perceived that it put forth a very fine point from its sucker, with the end of which it felt four or five spots of my skin, apparently with the design of discovering where it could obtain the most blood with the least trouble §.” This fine point, Swammerdam imagined to be simple and indivisible, and says, "the point is so sharp that I could never observe the least breadth in it with the best microscopes I could procure, though if you put the edges of the sharpest razors, or the points of the *Holland's Plinie, xi. 2.

+ Mém. Soc. d'Hist. Nat. de Paris, iii. 390.
§ Mém. iv. 583.

Biblia Nat. i, 157.

finest needles or lancets before the microscope, you will easily see that they have visible breadth, and appear blunt, ragged, and dull." But Réaumur is not a little surprised at this, for Leeuwenhoeck and himself found this fine point composed of several needles, some of them barbed with teeth, as may be verified by pressing the instrument between the fingers. The magnified figures will give a clearer idea of the organ than the most minute description.

Magnified figures of the sucker of the gnat: a, the sucker in its sheath; b, half of the sheath broken off to show the sucker; c, the sucker developed to show its several parts; d, the barbed point of one blade of the sucker.

The sheath is composed of a flexible substance, and is employed, it would appear, for supporting and keeping steady the piercers during the process of penetrating into the skin. Besides this, Swammerdam says, "I should think that the acute and hollow extremity of the sheath is certainly introduced into the wound, and by means thereof the gnat afterwards sucks the blood, which running or ascending by suction between these parts, is at length conveyed