NYMPHALIDyE. HII'PAIICH I A. 73 



is sometimes so close, that the most experienced eye can scarcely 

 detect the difference between them ; that in some cases it is almost 

 impossible to separate the individuals of such species, when variable, 

 unless guided by experience of their habits and localities ; and that 

 it is sometimes impracticable by any form of words to convey an 

 adequate idea of their relative distinctions to another person ; in fact, 

 as Mr. Bicheno has well observed, those species can only be de- 

 tected by that tact which he has termed empirical ; — yet, regardless 

 of the continually repeated instances of such occurrences, there are 

 not wanting individuals who assert that every newly discovered 

 species is a mere variety of its nearest congener, unless they happen 

 either to capture it, or to possess specimens; thereby sacrificing 

 two important considerations : first, that it is he alone who is 

 capable of giving the requisite examination to the specimens who 

 has them in possession ; and, secondly, their want of experience, 

 when they have neither captured nor seen the insects at large. Why 

 do not these entomologists, who thus dogmatically controvert the 

 discoveries of others, inform their brethren, if the love of science be 

 their idtimate aim, in what the essence of a species consists ? and 

 how they are able thus decisively to determine instantly upon the 

 specific identity of every specimen ? They will probably answer 

 these first in the words of Mr. Kirby, who truly says, " A species 

 is a natural object, whose differences from those nearly related to 

 it had their origin when it came from the hands of its Creator; 

 while those that characterise a variety have been produced since 

 that event*." But by what means they are enabled iincrringhj 

 (as they assume) to discover those characteristics, which distinguish 

 the species from the variety, I am totally at a loss to conjecture: 

 though as their opposition is frequently excited on account of the 

 close approximation of the species, need they be remimied that the 

 highest of all sciences, mathematics, requires the greatest degree of 

 exactness, and yet a rigid attention to its utmost minutia; is abso- 

 lutely indispensable.? It is therefore not surprising, that in the 

 examination of zoological subjects a closer inspection than a mere 

 prima facie view should be necessary before we become thoroughly 

 acquainted with them. 



I have thought fit thus to combat the above points, and to extend 

 these remarks, as, in consequence of venturing to add to the nundier 



• Kirby and Sp. Int. v. iv. p. 39G. 

 Haustellata. Vol. T. 1st March, 1828. 



