76 



MALACOLOGY. 



to those circulating red blood. In olden times these 

 singular animals appear to have been but little known, 

 and Aristotle, the father of naturalists, gives the name 

 of mollusc to such only as were naked, and that of 

 Ostracodermes to those clothed with a testaceous 

 covering ; the first he defines as creatures without 

 blood, whose fleshy parts are external, and the solid 

 portions internal, the converse for all the others. 



Linnaeus, adopting the same view, gives, with his 

 admirable perspicuity, the following definition : MOL- 

 LUSCA; h.slmplicia, nudn absque testa, artubusinstructa, : 

 TESTACEA ; A. simplicia domo s&piui calcario obtucta. 

 He and his disciples, merely attending to the charac- 

 ters of external configuration, lost sight of the natural 

 affinities of these animals affinities highly important 

 to connect the chain of evidence in forming a system, 

 .and which can only be traced by a minute examina- 

 tion of the structure and functions of all the combined 

 organs ; a want of this care, for it can hardly be at- 

 tributed to ignorance in that great man, has led to 

 .numberless errors and false conclusions ; in the same 

 genus animals were named respiring air, associated 

 with others which perform the same function by 

 means of gills in water ; animals whose gills are like 

 laminae, or leaves placed externally, with those having 

 their gills situated in an internal cavity. And with 

 regard to his classification of shells, independent of 

 their inhabitants, many anomalies exist that should 

 not have escaped the generally accurate judgment of 

 such a naturalist, but proving the liltle attention he 

 'paid to this portion of nature. Notwithstanding 

 .these errors (and what system can be free from them ?) 

 ' notwithstanding the necessity of the present clas- 

 sification from the increased knowledge we have ac- 

 . quired, the Linnsean system .will always remain a 

 kevrstone in the circle of natural history, 

 ; Fabiu<s, Columna, Lister, Willis, Swammerdam, 

 .and others, vainly published anatomical descriptions 

 .of Mollusca, with a view to establish a systematic 

 .arrangement of them in combination with their shells ; 

 .no one possessed courage to carry on the scheme 

 -they suggested. Linnaeus does indeed mention, in 

 the first editions of his Sy sterna Natura?, the animal 

 -before a description of the shell ; but he confined 

 .himself to naming that with which the shell appeared 

 to have the greatest connexion, and his genera of 

 ; conchology are merely formed on the external con- 

 , figuration of the shell alone ; in this he was followed 

 by the greater portion of naturalists of the last cen- 

 tury. Molluscs, as they are now viewed, may in 

 general terms be thus described; animals whose 

 .bodies and appendages of vitality are soft, and not 

 articulated.; they are enveloped in a muscular cover- 

 ing or skin, called the mantle, the form of which is 

 .extremely various in the different genera and spe- 

 cies, and .within or upon which exists what is called 

 .the shell, either univalve or consisting of one piece, 

 bivalve or consisting of two pieces, or multivalve 

 .and consisting of more than two pieces, some without 

 .any rudiment of shell. These animals possess a per- 

 fect circulation of white or rather bluish blood, an 

 aortic heart, with arterial and venous vessels, within 

 which the blood circulates ; they respire by branchiae ; 

 ,the brain is a distinct mass, from which the nerves 

 .and medulla oblougata proceed ; and there are gan- 

 glions in different parts of the body, that of locomo- 

 tion being lateral ; the senses vary ; some of these 

 animals possess distinct organs of sight and hearing, 

 .while others appear to be confined to trie senses of 



touch and taste. They are for the most part very 

 low in the scale of creation ; but the Sepia, or cuttl 

 fi$h, presents an extremely perfect organisation, since 

 it enjoys all the animal faculties of seeing and hear- 

 ing well, and moving from on spot to another with 

 ease and rapidity, and of being consequently able to 

 pursue and seize its prey with the utmost facility ; 

 others, on the contrary, live arid die on the spot 

 which gave them birth, and depend, during the span 

 of their existence, entirely upon adventitious circum- 

 stances for their sustentation ; each, however, let it 

 always be reverentially remembered, performing an 

 important duty in the scheme of infinite goodness 

 and wisdom, far beyond our judgment to fathom. 



It would be to us a delightful task to trace the 

 march of intellect from the earliest writers on the natnnil 

 history of this and other portions of nature down to the 

 present time ; to enumerate the various lights thrown 

 upon its study by the unwearied exertions of learned 

 men ; and to sum up the moral and physical benefits 

 mankind derive from it ; but time and space prevent 

 our doing so. We can, therefore, only sketch a very 

 faint outline of the advance this science has made, in 

 defiance of all the difficulties that surround its study 

 and retard its progress, in the way that has marked all 

 the other portions of the animal kingdom, since of 

 those to whom an opportunity is afforded of seeing 

 these animals, but a small number possess the requisite 

 knowledge to give a correct description of their struc- 

 ture, and travellers' sights may easily be magnified 

 into marvellous tales when resting only on the crea- 

 tive evidence of imagination. We, nevertheless, 

 most earnestly recommend our readers, at all period* 

 of life, to pursue a knowledge, always easily attained, 

 of some one branch of nature, not only as an endless 

 source of the highest ralional enjoyment, combined 

 as it were with the development of a new sense of 

 feeling, but, as we firmly believe, beyond all other 

 pleasures conducive to render them happier because 

 better men, through the instruction every page of 

 nature affords to those who are willing to read it in 

 the simple language of truth and piety. How admi- 

 rably has the poet said that there are 



Tongues in trees, books in the running streams, 

 Sermons in stones. 



But a mind unused to examine or reason upon 

 natural facts, perceives neither beauty or novelty in 

 the wonderful changes silently going on around us 

 daily ; their uniform progress having been from the 

 beginniiig of time, is always coeval with ourselves ; 

 and, without a necessity for our active interference, 

 the senses become imperceptibly reconciled to their 

 regularity, an indifference is engendered to the phe- 

 nomena of nature, they take place and pass away, 

 leaving no impression behind them, when viewed, as 

 they but too frequently are, as things of course, with 

 which we have nothing to do. When, however, a 

 spirit of scientific inquiry is roused, a taste imbibed 

 lor the investigationof nature's operations ; when the 

 energy of the mind is once applied to trace, as far as 

 may be, the effects of general causes, to attempt an 

 elucidation of some of the laws by which these are 

 governed, every living thing then assumes a new as- 

 pect : at each step fresh matter for wonder atid reflec- 

 tion presents itself; we behold all the mysterious 

 effects of chemical combinations, all the powers of 

 mechanical principles, every thing that governs matter 

 or motion, exercised in nature to a degree of pert'ec- 



