I C E 



657 



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IctUwL yelling is practicable, presents a strong obstacle. Yet 

 - - ' we hope that wine able mineralogists will repeat and 

 extend the observations made by Sir George Macken- 

 zie, and avail themselves of the information afforded by 

 that gentleman. 



We understand that the celebrated traveller and mi- 

 neralogist Baron Von Buch, has carefully examined the 

 Icelandic collection in the cabinet of the Royal Society 

 of Edinburgh, and has the intention of soon communi- 



cating to the public the result of his examination of va- 

 rious volcanic countries. 



See Leltert on Iceland, by Von Troil ; Voyage en 

 Itlande, fait par ordre de sa Majeste Danois, par MM. 

 Paulsen et Olafsen ; Hooker's Tour in Iceland, ISOff ; 

 Travels in Iceland, 1810, by Sir G. S. Mackenzie; 

 Transaction! of the Royal Society of Edinburgh, vols. 

 iii. and vii. See also the article VOLCANO, which Baron 

 Von Buch has promised to write for this work. 



ICHTHYOLOGY. 



Ichthjo- ICHTHYOLOGY is that department of natural history 



lofj. which treats of FISHES, classifying them according to 



* "V ^ their forms, ascertaining their haunts, describing their 



manners, and specifying the uses to which they may 



be applied. The title of the science is a compound of 



two Greek words, 'x'w ajith, and >*-/< a discount. 



Fishes belong to that great division of animals, cha- 

 racterised by having an articulated skeleton, a bony 

 cavity containing the brain, a spinal marrow, and red 

 blood. They are thus associated with quadrupeds, 

 birds, and reptiles, from which, however, they may 

 be distinguished by the following characters. 



Fishes possess a bean with one auricle and one ven- 

 tricle. The blood is cold. They are destitute of 

 windpipe and lungs, breathing by means of peculiar 

 organ* termed gill*. They re-ode in water, are in ge- 

 neral covered with scales, and swim by the assistance 

 of fins. 



The ancients regarded as fishes, all animal* which 

 seek their food in water, or which reside in that ele- 

 ment. Hence we find whales included by older wri- 

 ters among fishes, constituting a subdivision, distin- 

 guished by their breathing by means of lungs. But 

 cetaceous animals differ from fishes, not merely in their 

 organs of respiration, but likewise in those of circula- 

 tion and reproduction. Their heart consists of two au- 

 ricles and two ventricles, and the blood is warm. They 

 bring forth their young alive, and suckle them. 



more difficult to draw the line of distinction be- 

 tween fishes and reptiles. The structure of the heart, 

 and the temperature of the blood, are similar in both 

 rlassrs Reptiles, however, are all furnished with lungs ; 

 a*d although, in a few genera, the young are possessed 

 of gills, yet these organ* disappear before the animals 

 Arrive at maturity. There are, however, two genera in 

 which the gills are pendstent, but the animals belong- 

 ing to these have digitated feet, and are not likely ever 

 to be confounded with fishes. 



The study of this department of natural history is 

 peculiarly difficult. The element in which fifhei re- 

 side conceal* their movements from our view, and pre- 

 vents us from becoming acquainted with their instincts 

 and habits. In the midst of lakes and riven, in the 

 depths of the ocean, or in pools on the less frequented 

 shores, they perform unmolested the great operations 

 of nature. Hence the manner of their production, the 

 appearances exhibited by the different sexes, the changes 

 produced by age or season, the artifices they employ to 

 obtain their food, the migrations which they perform, 

 and thr limits of their existence, have hitherto been but 

 imperfectly ascertained. 



The rarer kinds of fishes, occasionally found on the 

 hooks ii- in the nets of fishers, are rejected by them as 

 seiess, or perhaps exhibited for a few days in the 



VOL. II. PART II. 



neighbouring village as objects of wonder. They speed- 

 ily decay, and the only memorials of their existence 

 are preserved in the imperfect traditions of their form. 

 It rarely happens that an intelligent naturalist is on 

 the spot to examine their characters, or to delineate 

 their appearance. But even should there be a person at 

 hand capable of forming a systematic description, still 

 their haunts and habits must remain unknown to us. Of 

 the various species of fi-hcs enumerated by nomencla- 

 turists, perhaps more than the one half are known to 

 us only by their external forms ; their food, their in- 

 stincts, and their functions, remaining unascertained. 



The pursuits of the ichthyologist are fur from pos- 

 sessing those charms which excite the zeal and admira- 

 tion of the naturalist in other departments of zoology. 

 It is easy, indeed, to form a collection of these objects, 

 and to preserve their form and characters for scientific 

 purposes; but a museum furnished with such specimens, 

 presents little that is gay or splendid. The colours 

 and lustre of fish fade alter death, nor can any process 

 of embalming fix and preserve them. A coating of var- 

 nish is often resorted to as a substitute for the natural 

 slimy covering of their skins, and the brush is employed 

 to restore the colours ; but specimens prepared in this 

 manner are disregarded by the scientific observer, and 

 to the mere spectator a collection of fishes in wax- work 

 would be equally acceptable. The aspect of some fishes, 

 as the eel for example, is repulsive ; while the cold moist 

 surface of others, disgust the fastidious naturalist, or at 

 least lessen his anxiety to examine this portion of ani- 

 mated nature. 



These impediments to the study of ichthyology have 

 unquestionably retarded the progress of the science ; 

 but we are confident, that the advantages which result 

 from an attentive examination of the subject, may be 

 placed in successful opposition. The rank which lislies 

 hold in the scale of being, as connecting the vertebral 

 with the molluscous animals, is alone sufficient to awa- 

 ken curiosity ; while a considerable degree of interest 

 is excited, by attending to those forms and organs 

 which fit them fur residing in the waters. But this de- 

 partment of zoology is not occupied exclusively with 

 matters of mere curiosity or science ; the subject is of 

 vast importance in an economical, n commercial, and a 

 national point of view. The inhabitants of this coun- 

 try derive a large portion of their subsistence from the 

 waters ; nor could one half of the present population of 

 the country be supported, were access to this great 

 storehouse of life and nourishment cut off*. 



In confirmation of this assertion, we request the rea- 

 der to consider the countless number!) of cod, herrings, 

 haddocks, turbot, skate, mackrel, and pilchards, annually 

 furnished to us by the ocean, and the salmon, pikes, perch- 

 es, and trout* captured in our lakes and rivers. A part 

 4o 



Irhthys- 

 logy. 



