ICHTHYOLOGY.

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it has no fins on its belly; the haddock seems to be more com-pletely fitted for motion, and yet it does not move so swiftly.Kay, some fishes which have no lins at all, such as lobsters, dartforward with prodigious vapidity, by meims of their tail. Hencethe instrument of progressive motion, in all fishes, is now conclud-ed to be the tail. The great use of the fins is to keep the body inequilibrio: if the fins are cut off, the fish can still swim, but willturn upon its sides or its back, without being able to keep itsellin an erect posture as before. If the fish desire to turn, an exer-tion of the tail turns it about in an instant; but if the tail strikeboth ways, then the motion is progressive. All fishes are furnishedwith a slimy glutinous matter, which defends their bodies from theimmediate contact of the surrounding fluid, and which likewise,in all probability, assists their motion through the water. Beneaththis, in many kinds, is found a strong covering of scales, which,like a coat of mail, defends it still more powerfully; and underthat, above the muscular parts, lies an oily substance, which alsotends to preserve the requisite fvarmth and vigour. _ Fishes areconsidered by many naturalists as of a nature much inferior to land-animals, whether beasts or birds. Their sense of feeling, it isthought, must be very obscure on account of the scaly coat of mailin winch they are wrapped up. Their sense of smelling al.o, it is'-aid, they can have only in a very small degree. All fishes, in-deed, have one or more nostrils; and even those that have not theholes perceptible without, yet have the bones within, properlyformed for smelling. But as the air is the only medium we knowproper for the distribution of odours, it cannot be supposed thatthese animals which reside constantly in the water can be affectedby them. As to lasting, they seem to make very little distinc-tion. The palate of most fishes is hard and bony, and consequentlyIncapable of the. power of relishing different substances; and ac-cordingly these voracious animals have often been observed tov 'vallow the fisherman’s plummet instead of the bait. Healing isgenerally thought to be totally deficient in fishes, notwithstandinghie discoveries of some anatomists who pretend to have found outb’.e bones designed for the organ of hearing in their beads. Theynave no voice, it is said, to communicate with earb other, andconsequently have no need of an organ for hearing. Seeing seemsfo lie the sense of which they are possessed in the greatest de-and yet even this seems obscure, if wc compare it with that’’1 other animals. The eye, in almost all fishes, is covered withfoe same transparent skin which covers the vest of the head, and"hieli probably serves to defend it in the water, as they have noeyelids. The globe is more depressed anteriorly, and is furnished.iPliind with a muscle which serves to lengthen or flatten it as there^ occasion. The crystalline humour, which in quadrupeds isa t and of the shape of a button-mould, or like a very convex lens,ji fishes is quite round, or sometimes oblong Hence it isought that fishes are extremely near-sighted; and that, even in>e water, they can perceive objects only at a t’ery small distance,cnee, (say they,) it is evident how Far fishes arc below terrestrialp'nnals in their sensations, and consequently in their enjoyments.of'.*' 11 - ^ ,e ' r brain, which in all animals is by some supposed to beY a Slze proportionate to the understanding, shews that fishes arey 1 - much inferior to birds in this respect. Others argue diffe-a ’ 1 I' w ‘ t * 1 'Tgard to (lie nature of fishes. With respect to thedef e - ° f feelu, S- sa >' biev, it cannot be justly argued that fishes arePoso'T'S merti *y because they are covered with scales, as it is-‘ble these scales may be endued with as great a power of sen-"’ecan ' nia S'"e. The sense of feeling is not properlyifiniii'T 0 ' "softness in any organ, more than with hardness. Ado n ' 1 } a L rRumcilt 'surged with regard to smelling ; for though weProof tl * no ' v bow smells can he propagated in water, that is nopable T V 10 -' are notso - On the contrary, as water is found ca-Pfobal I. absorbing putrid effluvia from the air, nothing is moretp r i , n .fbat these putrid effluvia, when mixed with the \va-f"et fhc olfactory organs of fishes, as well as (hey af-

’-ertain^ri ei - m ’ xec ^ "'th the air. With regard to fast*', it is"’bat is’’ lat hshes are able to distinguish their proper food fromwial se ' mp , r T r ’ aS ' vc " as °*ber animals. But no voracious ani-' v °uld it * S i it eM< ' l|ie ' < l with much sensibility in Ibis respect; nor"outing iv°. >a ’T be consistent with that way’of promiscuously de-V ,p »e f-reature that comes within its read), without which

bearing 0 f y "".'fflals could not subsist. With respect to the* les » it is urged, that, when kept in a pond, they may

be made to answer at the call of a whistle or the ringing of a belt ;and they will be terrified at any sudden and violent noise, such asthunder, the firing of guns, &c. and shrink to the bottom of thewater. Among the ancients, many were of opinion that fishes hadthe sense of hearing, though they were by no means satisfiedabout the ways or passages by which they heard. Placentini af-terwards discovered some bones in the head of'the pike, whichhad very much the appearance of being organs of hearing, thoughhe could never discover any external passages to them. Klin af-firmed, from his experiments and observations, that all fishes have’,the organs of hearing ; and have also passages from without tothese organs, though in many species they" are not easily seen;and that even the most minute and obscure of these are capableof communicating a tremulous motion to those organs, from soundsissuing from without. This is likewise asserted by M. Geoffiov,who gives a particular description of the organs of hearing belong-ing to several species. Dissert, sur 1’organe de Fouie, p. 07, etseq. These organs are a set of little bones extremely hard, andwhite, like fine porcelain, which are to be found in the heads of allfishes: the external auditory passages are very small ; beingscarcely sufficient to admit a hog’s bristle; though with care theymay be distinguished in almost all fishes. Water cannot be thought:an improper medium of sound, seeing daily experience shews usthat sounds may be conveyed not only through water but throughthe most solid bodies. (See Acoustics.) It seems indeed verydifficult to determine the matter by experiment. Mr. Gouan,who kept some gold-fishes in a vase, informs us, that whatevernoise lie made, he could neither terrify nor disturb them ; he hal-loo’d as loud as fie could, putting a piece of paper between hismouth and the water, to prevent the vibrations trom affecting thesuriace, and the fishes still seemed insensible ; but when the paperwas removed, and the sound had its full effect on the water, Un-case was then altered, and the fishes instantly sunk to the bottom.This experiment, however, cannot prove that the fishes did no):hear the sounds before lhe paper was removed ; it only shews thatthey were not alarmed, till a sensible vibration was introducedinto the water. The call of a whistle may also be supposed to af-fect the water in a fish-pond with a vibratory motion; but tinscertainly must be very obscure; and if fishes can be assembled inthis manner when no person is in sight, it amounts to a demonstra-tion that they actually do hear. Bee Zootomy. The argumentsused against the sight of fishes are the weakest of all. Many in-stances which daily occur, shew that fishes have a very acute sight,not only of objects in the water, but of those in the air. Theirjumping out of the water to catch fiies is a decisive proof of this ;and this they will continue to do in a fine summer evening,even af-ter it is so dark that we cannot distinguish the insects they attemptto cutch.Though fishes are formed for living entirely in the water,yet they cannot subsist without air. On this subject Mr. Ilawks-ix-e made several experiments, which are recorded in the Philos.Trans. The fishes he employed were gudgeons; a species thatare very lively in the water, and can live a considerable time outof it. 'I’hree of them were put in a glass with about three pints offresh water, which was designed as a standard to compare theothers by. Into another glass, to a like quantity of water, were,put three more gudgeons, and thus the water filled the glass lo thevery brim. l T pon this be screwed down a brass-plate with a lea-ther below, to prevent any communication between the water andthe external air; and that it might the better resemble a pondfrozen over, he suffered as little air as possible to remain on the,surface of the water. A third glass had the same quantity of waterput into it; which, first by boiling, and then by continuing it awhole night in vacuo, was purged of its air as well as possible ;and into this also were put three gudgeons. In about half an hourthe fishes in the water, from whence air had been exhausted, began,lo discover some signs of uneasiness by a more than ordinary mo-tion in iheir mouths and gills. Those who had no communicationwith the external air would at this time also frequently ascend tothe top, and suddenly swim down again : and in this state theycontinued for a considerable time, without any sensible alteration.About five hours after this observation, the fishes in the exhaust-ed water were not so active as before, upon shaking the glasswhich contained them. In three hours more the included fisheslav all at the bottom of the glass with their bellies upwards ; norcould they be made to shake their fins or tail by any -uotioa given