OBJECTIONS CONSIDERED. 125 



Sucli is the ingenious piece of special pleading which this 

 most popular of the Lamarckians directs against the standing 

 and organization of the earlier fishes. Let us examine it 

 somewhat in detail, and see whether the slight admixture of 

 truth which it contains serves to do aught more than to ren- 

 der current, like the gilding of a counterfeit guinea spread 

 over the base metal, the amount of error which lies beneath. 

 I know not a better example than that which it furnishes, of 

 the entanglement and perplexity in which the meshes of an ar- 

 tificial classification, when converted, in argumentative pro- 

 cesses, into symbols and abstractions, are sure to involve sub- 

 jects simple enough in themselves. 



Fishes, according to the classification of a preponderating 

 majority of the ichthyologists that have flourished from the 

 earliest times down to those of Agassiz, have been divided 

 into two great series, the Ordinary or osseous, and the Chon- 

 dropterygii or cartilaginous. And these two divisions of the 

 class, instead of being ranged consecutively in a continuous 

 line, the one in advance of the other, have been ranged in 

 two parallel lines, the one directly abreast of the other. There 

 is this further peculiarity in the arrangement, that the line of 

 the cartilaginous series, from the circumstance that some of 

 its families rise higher and some sink lower in the scale than 

 any of the ordinary fishes, outflanks the array of the osseous 

 series at both ends. The front which it presents contains 

 fewer genera and species than that of the osseous division ; 

 but, like the front of an army drawn out in single file, it ex • 

 tends along a greater length of ground. And to this long- 

 fronted series of the cartilaginous, or, according to Cuvier, 

 Chondropterygian fishes, the placoid families of Agassiz belong, 

 — among the rest, the placoids «»f the Silurian formations. 

 Upper and Lower. But though all the placoids of this latter 

 naturalist be cartilaginous fishes, all cartilaginous fishes are 

 not placoids. The Sturionidce are cartilaginous, and are, as 



