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Sucking Fish.

[Book II

ceeds a ton in weight, is furnished by the Creator with analogous apparatusin his hinder feet; and thus climbs by atmospheric pressure, the glassy sur-faces of ice-bergs. How forcibly do these examples illustrate the intimateConnection which subsists between the various departments of Natural Phi-losophy. A knowledge of one always furnishes a key (whether it be used ornot) to open some of the mysteries of another. Thus a person who under-stands the principle by which water is raised in a simple pump,can by it ex-plain some of the most surprising facts in the natural history of animals;and solve problems respecting the motions and Organs of motions of nu-merous tribes of animated beings, which two or three centuries ago, themost enlightened philosophers could not comprehend. And with a simplepump, he can moreover determine, as with a barometer, the measurement ofall accessible heights, and with a degree of accuracy that, in some cases,is deemed preferable to geometrical demonstrations.

When two substances are brought together, at some distance helow thesurface of water, and so as to exclude it from between them, they arethen pressed together with a force greater than when in the air, be-cause the weight of the perpendicular column of water over them isthen added to that of the atmosphere. Numerous examples of this com-bined pressure are also to be found in the natural World. By it, variousspecies of fish adhere to rocks and stones in the depths of the sea, fromwhich they cannot be separated except by tearing their bodies asunder.Some by means of it attach themselves to the bodies of others, and there-by traverse the ocean without any expense or exertion of their own, some-what like dishonest travelers, who elude the payment of their fare. Thereare several species of fishes known which have a separate organ of adhe-sion, and there are doubtless many more which have not yet come underthe observation of man. The most celebrated is the remora or suckingfish of Dampier and other navigators. It is, in size and shape, similar toa large whiting, except that the head is much flatter. “ From the head tothe middle of its back, (observes Dampier) there groweth a sort of flesh ofa hard gristly substance, like that of the limpet. This excrescence is of aflat oval form, about 7 or 8 inches long, and 5 or 6 broad, and rising abouthalf an inch high. It is full of small ridges with which it will fasten itselfto any thing that it meets with in the sea. When it is fair weather andbut little wind, they will play about a ship, but in blustering weather, orwhen the ship sails quick, they commonly fasten themselves to the ship’sbottom, from whence neither the ship’s motion, though never so swift, northe most tempestuous sea can remove them. They will likewise fastenthemselves to any bigger fish, for they never swim fast themselves, if theymeel with any thing to carry them. I have found them sticking to a sharkafter it was hal’d in on deck, though a shark is so strong and boisterous afish, and throws about him so vehemently when caught, and for half anhour together, that did not the sucking fish stick at no ordinary rate, itmust needs be cast off by so much violence.” a They are familiär to mostof our seamen. Other species have a circular organ of adhesion, eonsist-ing of numerous soft papillas, and placed on the thorax, instead of thetop of the head, as in the remora. In some fish the ventral fins are unitedand are capable of adhesion. In the lamprey the mouth contracts and

“Dampier’s Voyages, vi. edit. 1717, Vol. i, (14, and Vol. ii, part iii, p. 110. In thethe plates of Vol. iii, is a figure of one. Figures of the excrescence or sucking partof the remora, and of the feet of the house-fly, may be seen in Dr. Brewster’s Letterson Natural Magic.