i28 HISTORY OF ZOOLOGY. 



" There then remains an . innumerable quantity of fishes, to which 

 we can no longer apply any characters except those of the exterior 

 organs of motion. After long examination, I have found that the 

 least bad of these characters is, after all, that employed by Ray and 

 Artedi, taken from the nature of the first rays of the dorsal and of the 

 anal fin. Thus ordinary fishes are divided into MALACOPTERYGIANS, 

 of which all the rays are soft, except sometimes the first of the dorsal 

 fin or the pectorals ; and ACANTHOPTERYGIANS, which have always 

 the first portion of the dorsal, or of the first dorsal when there arc 

 two, supported by spinous rays, and in which the anal has also some 

 such rays, and the ventrals, at least, each one. 



"The former may be subdivided without inconvenience, according 

 to their ventral fins, which are sometimes situate behind the abdomen, 

 sometimes adherent to the apparatus of the shoulder, or, finally, are 

 sometimes wanting altogether. 



"We thus arrive at the three orders of ABDOMINAL MALACOPTERT- 

 GIANS, of SUBBRACHIANS, and of APODES ; each of which includes 

 some natural families which \ve shall explain: the first, especially, is 

 very numerous. 



"But this basis of division is absolutely impracticable with the 

 Acanthopterygiaus ; and the problem of establishing among these any 

 other subdivision than that of the natural families has hitherto 

 remained for me insoluble. Fortunately several of these families offer 

 characters almost as precise as those which we could give to true orders. 



" In truth, we cannot assign to the families of fishes, ranks as 

 marked, as for example, to those of mamrnifers. Thus the Chondro- 

 pterygians on the one hand hold to reptiles by the organs of the senses, 

 and b'y those of generation in some ; and they are related to mollusks 

 and worms by the imperfection of the skeleton in others. 



" As to Ordinary Fishes, if any part of the organization is found 

 more developed in some than in others, there does not result from this 

 any pre-eminence sufficiently marked, or of sufficient influence upon theij 

 whole system, to oblige us to consult it in the methodical arrangement 



" We shall place them, therefore, nearly in the order in which we 

 have just explained their characters." 



I have extracted the whole of this passage, because, though it is too 

 technical to be understood in detail by the general reader, those who 

 have followed with any interest the history of the attempts at a natu- 

 ral classification in any department in nature, will see here a fine 

 example of the problems which such attempts propose, of the difficul- 



