37° 



Classification of Fishes 



gradations of likeness which are observable in animal structures, 

 and its objects and uses are manifold. In the first place, it 

 strives to throw our knowledge of the facts which underlie, 

 and are the cause of, the similarities discerned into the fewest 

 possible general propositions, subordinated to one another, ac- 

 cording to their greater or less degree of generality; and in 

 this way it answers the purpose of a memoria technica, without 

 which the mind would be incompetent to grasp and retain the 

 multifarious details of anatomical science." 



Coues on Classification. — It is obvious that fishes like other 

 animals may be classified in numberless ways, and as a matter 

 of fact by numberless men they have been classified in all sorts 

 of fashions. "Systems," again quoting from Dr. Coues, "have 

 been based on this and that set of characters and erected from 

 this or that preconception in the mind of the systematist. . . . 

 The mental point of view was that every species of bird (or of 

 fish) was a separate creature, and as much of a fixture in nature's 

 museum as any specimen in a naturalist's cabinet. Crops of 

 classifications have been sown in the fruitful soil of such blind 

 error, but no lasting harvest has been reaped. . . . The 

 genius of modern taxonomy seems to be so certainly right, to 

 be tending so surely even if slowly in the direction of the desired 

 consummation, that all differences of opinion we hope will soon 

 be settled, and defect of knowledge, not perversity of mind, is 

 the only obstacle in the way of success. The taxonomic goal is 

 not now to find the way in which birds (or other animals) may 

 be most conveniently arranged, but to discover their pedigree, 

 and so construct their family tree. Such a genealogical table, 

 or pJiylnm {(pvXov^ tribe, race, stock), as it is called, is rightly 

 considered the only taxonomy worthy the name — the only true 

 or natural classification. In attempting this end, we proceed 

 upon the beHef that, as explained above, all birds, hke all other 

 animals and plants, are related to each other genetically, as 

 oft'spring are to parents, and that to discover their generic 

 relations is to bring out their true affinities — in other words, to 

 reconstruct the actual taxonomy of nature. In this view 

 there can be but one ' natural ' classification, to the perfecting 

 of which all increase in our knowledge of the structure of birds 

 infallibly and inevitably tends. The classification now in use 



