^ SHELLS AND SHELL-FISH. PART I. 



hundreds of our readers may pass their lives without 

 seeing one, save the slugs in their gardens, or the 

 empty shells they once inhabited. Their aspect to the 

 ordinary observer is strange and unprepossessing, with- 

 out either the gracefulness of form, the activity of 

 motion, or the richness of colouring which ornaments 

 insects and vertebrated animals. Their manners and 

 economy scarcely come within our cognisance, for their 

 actions are carried on in an element we do not in- 

 habit ; hence they are rarely witnessed, and a few 

 partial details is all that has yet been gathered to eluci- 

 date their history. Their soft and slimy bodies cannot 

 be preserved so as to interest us even by their appear- 

 ance, or to become objects of beauty or of popular 

 interest ; they are, in short, almost passed, '' unheeded 

 and unknown," except by the eye of Science. 



(2.) The object of the series of volumes we are now 

 producing, is, to give to the world what has never yet 

 been attempted, — a philosophic survey of the works of 

 nature, based upon the harmonious relations which 

 every part bears to the whole. Partial systems, ap- 

 plicable to one branch only, and a crowd of anatomical 

 facts, have been either omitted, or but slightly touched 

 upon, as mere accessory helps to the paramount object 

 of our labours, ^^e have, indeed, got through the 

 almost herculean task of arranging the whole of the 

 Vertehrata according to their natural affinities and rela- 

 tions, even down to the sub-genera ; but to follow up 

 this plan with the annulose and the molluscous animals, 

 would not only swell the Cabinet of Natural History to 

 three times it prescribed limits, but would demand a 

 knowledge which, individually, would be superhuman. 

 The great truths, or, rather, the leading one, which the 

 enlightened reader should have constantly brought before 

 him is, the unity of plan in the creation : this might 

 be lost sight of, if the attention was long withdrawn 

 from such enlarged concei>tions, and occupied by a mul- 

 tiplicity of small details, fit only for the technical de- 

 scriber and the anatomical demonstrator. 



