ICHTHYOLOGY. 



INTRODUCTORY CHAPTER. 



SECT. I. DEFINITION AND GENERAL OBSERVATIONS. THE 



PRINCIPAL EPOCHS IN THE SCIENCE OF ICHTHYOLOGY. 



Fishes maybe technically defined as, vertehrated animals 

 viith red blood, breathing through the medium of water b;/ 

 means of braiichia or gills. Tliis definition, as Baron Cu- 

 vier has remarked, is the result of observation ; it is a pro- 

 duct of analysis, or wliat is termed in physics an empyrical 

 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 tlie beings to which it is applied. Being vertebrated, 

 they must be possessed of an internal skeleton ; of a brain 

 and spinal marrow, enclosed in a vertebral column ; of mus- 

 cles exterior to the bones ; of four extremities only ; and of 

 the organs of the first four senses, situate in the cavities 

 of the head ; witli other relations not necessary to be here 

 named. 



The greater portion of the surface of the earth is cover- 

 ed by the waters of the translucent sea ; and wherever con- 

 tinents and the larger islands protrude their rocky bulk, 

 we find them coursed by flowing rivers, or intersected by 

 lakes and marshes. These present in their aggregate an 

 enormous mass of waters, and afford protection and nou- 

 rishment to mjTiads of living creatures, probabl}' 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 conti- 

 nuance of vegetable species ; from these herbivorous ani- 

 mals draw their nourishment ; and this being animalized 

 by assimilation, becomes an appropriate food for the carni- 

 vorous kinds, which scarcely amount to more than one half 

 of the terrestrial creatures of all classes. But in the liquid 

 element, and more especially among the saline waters of the 

 ocean, where the vegetable kingdom is so much more re- 

 stricted, almost all organized substances are pervaded 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 ex- 

 tremes in respect to size, — from the myriads of microscopic 

 monads, which, but for artificial means, must have remain- 

 ed for ever invisible and unknown, to tlie ponderous whale, 

 which surpasses by twenty times the bulk of the largest 

 elephant. There, too, we may discover the majority of those 

 magnificent combinations of organic structure, on the rela- 

 tions 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 in- 

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



to dwell almost for ever on its waves. The mammiferous Introduc- 

 class is still more fully represented in the numerous tribes ''""• 

 of seals, morses, manaties, and whales, all of which require '■■^~^''~*^ 

 a moist abode, and some of which immediately perish 

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

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

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

 Zoophytes, — four great classes, which on terra fimia are kvf 

 and I'ar between, — exist in countless numbers in the waters 

 of the ocean. Hence that ancient dictum recorded by 

 Pliny, " Quicquid nascatiu- in ])arte natura; uUa, et in mari 

 esse ; pra;terque midta quae nusquam alibi." 



But amongst all the teeming wonders which vivify the 

 vast expanse and li(|uid depth of waters, none so predo- 

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

 present treatise ; nor are any more worthy of our devoted 

 consideration, whether we regard the beauty or eccentri- 

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

 or the innumerable benefits which, through the foresight 

 of Providence, they confer upon the human race. We there- 

 fore 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 interest 

 of the subject by a (ew general observations. 



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

 ally refrain from any bibliographical inquiry, or historical 

 exposition of the progress of Ichthyology. If such were 

 complete, or even ample, it wo\dd occupy too much of that 

 space which we deem more usefully devoted to the actual 

 condition of our subject-matter. W^e more willingly set 

 that department aside, when we consider how perfectly it 

 has been presented by Baron Ciivier.^ We shall, however, 

 briefly allude to what may be regarded as the principal 

 epocha in the progress of Ichthyological Science. 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 surprising 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, those who wrote on natural history 

 can scarcely be regarded in any other light than as either 

 copiers or commentators of Aristotle ; but about the mid- 

 dle of the sixteenth century, Belon, Rondelet, 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 

 1658. Differing from their compiling predecessors, they 



' From 'ix.^v!, a fish, and Xsycc, a discourte. 



* See the Tableau Ilhtoihjiic dcs Froi^rls de VJchiyotogk, dcpuh son orlgine jutqii'a nos jours,, m the first volume of his great though un- 

 fortunately uncompleted work, the Ilutoire NaUireUe dcs Fuissons. We deem ourselves fortunate beyond our predecessors in ency- 

 cloptedic labour, in having as a guide in so difficult a subject as that on which the reader is about to enter, the first nine volumes 

 of Baron Cuvier's signal publication. We should act unwisely were we to present a crude compendium of the works of foreign and 

 British writers, such as has hitherto sufficed for publications similar to that in which we are now engaged. We prefer adhering 

 throughout to Cuvier's system of arrangement, as one which, without doubt, is entitled to supersede all others hitherto proposed. We 

 shall also avail ourselves, wherever our doing so seems likely to instruct the reader, of whatever general or miscellaneous information 

 is scattered through his work, presenting it in a form and sequence the most advantageous to those unacquainted with the volumi- 

 nous original ; and adding, especially in relation to our native species, wliatever we find of interest in recent authors, among whom, as 

 elucidators of *' British i'ishes," Messrs Couch and Yarrell stand pre-eminent. We beg to make this general acknowledgment of the 

 infinite advantage we have derived from Baron Cuvier's labours, in the formation of the present treatise, in reference both to ouriu- 

 troductory and systematic portions. 



