PRELIMINARY OBSERVATIONS. 3 



and of honour, into the silent grave. The day, in short, 

 has gone by when mere opinions, unsupported by argu- 

 ments, will have any effect among those whom they are 

 intended to influence ; or when new systems, built on an 

 imperfect acquaintance with only one division of zoology, 

 will be at all regarded by those who can alone give them 

 notoriety; for higher naturalists have long dismissed the 

 idea of studying nature under such narrow and purblind 

 views. Our firm belief indeed is, that as these systems 

 of late have emanated only from students, their very 

 authors will throw them aside when greater experience 

 shows how artificial and futile they really are. 



(2.) In the two most perfectly organised classes of ani- 

 mals, quadrupeds and birds, we have endeavoured to 

 show the prevalence of these primary forms, and the 

 harmony that results from tracing their modifications. 

 We are now to make a similar effort in respect to the 

 remaining vertebrated classes. Our investigation, how- 

 ever, of the natural arrangement of these animals must 

 be conducted, in part, on a different plan to that we 

 have pursued in ornithology. We must occasionally 

 adopt the synthetical rather than the analytical process 

 of investigation; or, in other words, we must presume 

 that our propositions, in the abstract, are correct, and 

 that we have only to extend them to another class: we 

 do this, not from choice, but from necessity. In the 

 first place, the state of ichthyological science, to which 

 the greater part of our two volumes will be devoted, 

 however rapidly it has advanced in a knowledge of 

 groups and species, is, and long must be, from the very 

 nature of the animals upon which it treats, considerably 

 behind ornithology. Inhabiting an element whose re- 

 cesses cannot be explored by man, and with a peculiarity 

 of structure and of colouring which renders their bodies 

 very difficult to preserve, the natural history (properly 

 so called) of fishes, when compared with that of ter- 

 restrial animals, wiU ever remain little more than a col- 

 lection of a few superficial anecdotes ; while, from the 

 difiiculty of their preservation and the unattractive 



B 2 



