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204 



ICHTHYOLOGY/ 





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INTRODUCTORY CHAPTER. 



SECTION I. DEFIN'ITION AND GEXEIiAL OBSERVATIONS. THE 



PRINCIPAL EPOCHS IN THE SCIENCE OF ICHTHYOLOGY. 

 VERTEBRALS. 



Fishes may be technically defined as vertebrated animals 

 with red blood, hreutliuiii throuyh the iiiedivm of vcittr by 

 means of hraiiclii<c or yilts. This definition, as Baron 

 Ciivier has reniai'ked, is the result of observation ; it is a 

 pro(hict of analysis, or what is termed in physics an em- 

 pirical formula ; but its accuracy is demonstrable by the 

 inverse method, for, when once duly perceived, we may, 

 in a great measure, deduce from it a knowledge of the 

 entire nature of the beings to which it is applied. Being 

 vertebrated, they must be possessed of an internal skeleton ; 

 of a brain and spinal marrow, inclosed in a vertebral 

 column ; of muscles exterior to the bones ; of four extre- 

 mities only ; and of the organs of the first four senses, 

 situate in the cavities of the head ; with other relations not 

 necessary to be here named. 



The greater portion of the surface of tlie earth is covered 

 by the waters of the translucent sea ; and wherever conti- 

 nents and the larger islands ])rotrude their rocky bulk, we 

 find them coursed by flowing rivers, or intersected by lakes 

 and marshes. These present in their aggregate an enor- 

 mous mass of waters, and afford jirotection and nourishment 

 to myriads of living creatures, ])robably superior in number 

 and in no way inferior in beauty, to those which inhabit 

 the earth. On land, the matter susceptible of life is mainly 

 employed in the construction and continuance of vegetable 

 species ; from these, herbivorous animals draw their nourish- 

 ment ; and this being animalized by assimilation, becomes 

 an appropriate food for the carnivoroiis kinds, which 

 scarcely amount to more than one-half of the terrestrial 

 creatures of all classes. But in the liquid clement, and 

 more especially among the saline waters of the ocean, 

 where the vegetable kingdom is so much more restricted, 

 almost all organized substances are jiervaded by animal 

 life, and each lives at the expense of some smaller or feebler 



foe. 



There we meet not only with the greatest and most 



wonderful variety of forms, but also with the extremes in 

 respect to size, — from the myriads of microscopic monads, 

 which, but for artificial means, must have remained for 

 ever invisible and unknown, to the ponderous whale, which 

 surpasses, by twenty times, the bvdk of the largest elephant. 

 There, too, we may discover the majority of those magni- 

 ficent combinations of organic stnicture, on the relations 

 of which naturalists have established the distinction of 

 classes, or great primary groups ; in other words, the sea 

 may be said to contain representatives of each ; for, even 

 among birds, those aerial creatures which usually inhabit 

 so light an element, we find species so constructed as to 

 dwell almost for ever on its waves. The mammiferous 



class is still more fully represented in the mmierous tribes Introduc- 

 of seals, morses, manaties, and whales, all of which require ''o°- 

 a moist abode, and some of which inmiediately jierish ^•"^■V"^ 

 when deprived of it. Most reptiles are aquatic, many in- 

 sects are so, more particularly in their larva state ; and al- 

 most all the Mollusca, the Annelides, the Crustacea, and 

 Zoophytes, foia- great classes, which on terra Jirma are few 

 and far between, exist in coimtless nimibers in the waters 

 of the ocean. Hence that ancient dictum recorded by 

 Pliny, " Quicquid nascatm- in parte natura? uUa, et in mari 

 esse ; pra;terque multa ijua; nusquam alibi." 



But amongst all the teeming wo}iders which vivify the 

 vast expanse and licpiid depth of waters, none so jjredo- 

 minate, or are so truly characteristic, as the subjects of our 

 present treatise ; nor are any more worthy of oiu- careful 

 consideration, whether we regard the beauty or eccentri- 

 city of their forms, the metallic splendour of their colours, 

 or the innimierable benehts which, through the foresight 

 of Providence, they confer upon the himian race. We 

 therefitre deem it incumbent upon us to exhibit an ample 

 view of the present condition of Systematic Ichthyology ; 

 but before doing so, we shall endeavour to add to the in- 

 terest of the subject by a few general observations. 



We may state, in the first place, that we here intention- 

 ally refrain fi-om any bibliographical inquiry, or historical 

 exposition of the (jrogress of Ichthyology. If such were 

 complete, or even amjile, it would occupy too much of 

 that space which we deem more usefully devoted to the 

 actual condition of the science ; and we more willingly 

 set that department aside, when we consider how per- 

 fectly it has been presented by Baron Cuvier.' We shall, 

 however, briefly allude to what may be regarded as the 

 principal epoch in the jjrogress of Ichthyology. During 

 many remote ages it consisted, in common with all the 

 kindred branches of human knowledge, of nothing more 

 than a few partial and disjointed observations. Aristotle, 

 about 350 years before the Christian era, made some pro- 

 gress towards connecting these together as a body of doc- 

 trine ; but still it was a feeble body, reposing upon truths 

 (perceived indeed with surjirising skill when we consider 

 the scanty data) as yet obscurely known and vaguely ex- 

 pressed, owing to the entire absence of all proper standards 

 for the distinction of species. For more than eighteen 

 hundred years ensuing, the writers on natural history can 

 scarcely be regarded in any other light than as either 

 copiers or conmientators of Aristotle ; but about the mid- 

 dle of the sixteenth century, Belon, Kondelet, and Salviani, 

 the true founders of modern Ichthyology, made their ap- 

 pearance (we mean as authors), by a singular coincidence, 

 almost precisely at the same time, — the first in 1553, the 

 second from 1554 to 1555, and the third from 1554 to 

 1558. Differing from their compiling predecessors, they 

 saw and examined for themselves, and made drawings from 

 nature, if not with the elegant accuracy of modern days, at 

 least with a recognisable exactness. Yet, true to the ge- 



' From i^Pvs, a Jish^ and Xoyos, a discount. 



^ See the Tableau Historique dcs Progres de I'lchtyologie, depiiis son oriijine jusqu'a nos jours, in the first volume of the great though 

 unfortunately uncompleted work, the Histoire Naturelle dcs Pousons. We deem ourselves fortunate beyond our predecessors in ency- 

 clopaedic labour, in having as a guide in so difficult a subject as that on which the reader is about to enter, the volumes of Baron 

 Cuvier's and M. Valenciennes' signal publication. .\s far as this great work extends we have availed ourselves of the labours of it3 

 authors, and have endeavoured to present the general and miscellaneous information scattereil through it, as amply as our limits would 

 permit, and in a form and sequence the most advantageous to those unacquainted with the voluminous original. In the present revisal 

 of this treatise we have also borrowed freely from the writings of our British Cuvier, whose worli on the Comparative Anatomy and Pky- 

 swloyy of Fislics, forming part of his llunterian Lectures, gives the fullest and most accurate view of the animal economy of fishes, and 

 most philosophical account of the skeleton, that have hitherto appeared. "We beg also to repeat our acknowledgments to Mr Couch, the 

 acute discoverer and describer of new species frequenting the Cornish coasts, and .Mr Yarrell, whose work on Brititih Fishes is facile princej^s 

 among works illustrative of local Ichthyology. 



