qfM'Leay, Swainson, Vigors, fyc. 137 



capacious his mind ; he is but a man, and must bow to the 

 imperfection of which all mankind are participants. Nay, we 

 may often observe, that our wisest and most learned men are, 

 as it were, blinded by their own learning, and " common sense "* 

 is too common to have a place in their minds ; especially when 

 advocating a theory which, whether right or otherwise, they 

 have determined to establish ; a theory which, perhaps, common 

 sense might be fatal to. The Quinary System is the favourite 

 theory of Mr. Swainson: he has, although, as we are led to sup- 

 pose from his own words, contrary to the dictates of his com- 

 mon sense, laid down rules beforehand for natural groups'; and, 

 as those rules constitute the principal part of a theory which 

 he appears determined to establish, he attempts to compel na- 

 ture to bend to them ; and, in so doing, he breaks her laws, 

 and bids defiance to the requirements of natural affinity. It 

 would indeed be an endless task to recount the numerous in- 

 stances in which this is observable. To how many tribes, fa- 

 milies, sub-families, and genera are the remarks we have 

 made with respect to the orders applicable ! 



But this is not the only manner in which Mr. Swainson, by 

 forcing the application of his two primary propositions, has 

 broken the laws of natural affinity. Some groups do not 

 admit of division ; the animals which compose them are so 

 united by affinity, that we at once perceive that they are in- 

 tended by nature to constitute but one family, or genus. This, 

 however, will not do for Mr. Swainson's theory : he must 

 have five divisions to every group, or they will not conform to 

 his rules, or (to use his own words) " be natural." He there- 

 fore separates animals which are evidently approximate; 

 he divides mto Jive what, following nature, ought only to be 

 one. 



In some cases, however, circumstances will not admit of 

 this ; either on* account of the paucity of the species which 

 compose the group, or from the total absence of any 

 grounds on which, with the slightest show of sense, he could 

 construct any separation. From the same causes, also, Mr. 

 Swainson is not able to define the circular series of all such 

 groups. A person might be led to suppose that Mr. Swain- 

 son would either acknowledge these to be artificial according 

 to his theory, or give up the system at once, as being one 

 which cannot be substantiated. He would be strengthened in 

 his supposition by the author's remarks, which are given at 

 p. 340. of his Treatise : — • " Natural groups," says he, " are 

 thus to be detected by three different tests : 1. By their simple 

 series of circular affinity; 2. By the theory of analogy; and, 

 3. By the theory of variation. No group which will not bear 



