AND ON THE RELATIONS OF ANIMALS. 11 



but, labouring under this ignorance, are we to say that these 

 peculiarities have no connexion with the habits of the birds ? 

 Every thing we know of nature opposes the extravagant idea. 

 Besides, it so happens, that upon one of these birds our critic 

 is completely wrong, when he gives it as an instance of 

 " a repetition of structure, when function is not implied at all." 

 The horned screamer of Brazil has a real (spur-shaped) horn 

 upon its front, which is used as a defence, precisely as much as 

 are the horns of the bull or of the antelope. It is not, there- 

 fore, an instance of what our author calls resemblance, because 

 the structure is accompanied by the function. I have instanced 

 this bird as an example of analogy between the genus Pala- 

 media and the tribe of Runrinantia : both have horns used for 

 the same purposes, — so far there is a resemblance ; but the one 

 is a bird, and the others are quadrupeds, and this makes the 

 resemblance to be one of analogy. In like manner, the 

 horned and bulky Dynastidce are analogous, as Mr. Kirby 

 truly observes, to the same order of quadrupeds, and, con- 

 sequently, to the same genus of birds. For myself, I know 

 not of one animal in creation which will come under the 

 author's definition, either of analogy or resemblance. 



I think the Reviewer, or at least your readers, will admit 

 I have now given to each of these definitions every attention ; 

 without any attempt, knowingly, to pervert the meaning their 

 words would seem to convey. That the novel views contained 

 in the Preliminary Discourse, no less than the undisguised 

 opinions therein contained, would excite dissent and censure, 

 was naturally to be expected ; but when dissent is courteously 

 expressed, I am not only willing, but anxious, to excite discus- 

 sion ; for even if I am throughout in error, much good will 

 eventually result by such errors being detected. Posterity 

 will judge whether I am in a day dream; and whether my 

 Reviewer's concluding sentence upon my labours, that " they 

 will not do honour to the progress of Zoological science in this 

 country," is founded on an incapacity for comprehending them, 

 or in immutable truth. 



One concluding sentence. Knowing pretty well the sen- 

 timents of our leading naturalists, either personally or by their 

 writings, I have naturally been anxious to surmise which of 

 them could be the advocate of such singular opinions. Now 

 there is only one among us who adopts, or who advocates, the 

 Binary or Dichotomous system, — who excludes fossil from 



