40 ornithologist's text-book. 



some excellent remarks on the Dichotomous Sys- 

 tem — the one adopted by Fleming — in his Treatise 

 on the Geography and Classification of Animals, 

 and these we shall make no apology for transcrib- 

 ing:— 



" Binary or dichotomous systems, although re- 

 gulated by a principle, are among the most arti- 

 ficial arrangements that have been ever invented. 

 This great principle upon which the advocates of 

 such tables insist, simply consists in arranging 

 animals according to their positive and negative 

 characters; as, for instance, birds with perfect 

 wings, and, secondly, birds with imperfect wings; 

 and so on. Now this mode of arrangement is, 

 perhaps, the most simple, and the most easy of 

 comprehension, of any that has been devised ; and 

 was, therefore, the earliest in use. It likewise 

 seems to offer a ready clue to the discovery of any 

 particular species or genus, because the student has 

 no occasion to look beyond the table before him : 

 he need not trouble himself about affinities or ana- 

 logies, for he has merely to see what peculiar cha- 

 racter his specimen lias, and what it has not. — 

 When, therefore, his object is either to ascertain 

 the recorded name of a species, or whether it be 

 described or undeseribed, he will often find this 

 sort of catalogue useful. But the misfortune of 

 the binary methods of arrangement is this, that 

 they may be multiplied ad libitum. As their ad- 

 vocates profess not to pursue any one principle in 

 the selection of their characters, it follows that we 

 may have a hundred different binary systems, each 

 good in its way, but each different from the other. 

 One entomologist may choose to divide all insects 

 into such as have wings, and, secondly, such as 

 have none. Another, looking to the manner of 

 feeding, may make his two groups depend upon 

 one having jaws, the other none. A third, con- 



