500 Mr. Swainson and his Reviewers. 



Yet we can assure him that we know a great deal more about 

 these birds than he has told us. Both of them are common 

 and well-known species, and it was not till we had carefully 

 studied several specimens of each, that we ventured to term 

 them " important generic forms " of Muscicapida, — as Mr. 

 Swain son has defined the family. His definition of Musci- 

 capidce is as follows : — (' Classif. of Birds,' vol. ii. p. 254). 



" Stature small. Bill considerably depressed for its entire length, 

 broad : the edge of the upper mandible folding over that of the lower ; the 

 tip abruptly bent and notched. Rictus wide, defended with strong bristles 

 pointing forwards. Feet almost always short, small, and weak. Feed, sole- 

 ly upon insects captured during flight. Habits sedentary." 



" Now if any one will compare specimens of the white- 

 headed tody and the Muscicapa leucocilla with the above de- 

 finition, he will find that in all respects of structure they con- 

 form to it. Of the habits of these birds we do not pretend 

 to speak ; and if Mr. Swainson can inform us of any marked 

 peculiarity in this respect, we shall be obliged for the infor- 

 mation, and will allow it due weight in forming our opinion. 

 But judging from structure alone, it is clear either that these 

 birds are Muscicapidce, or that Mr. Swainson's definition of 

 that family should be altered so as to exclude them. 



" When we termed these birds " generic forms " we did not 

 mean to fix their precise value as compared with the genera 

 or the sub-genera of Mr. Swainson. Many, (we might say 

 most) naturalists disapprove of the term sub-genus, and pre- 

 fer following the rules of logic in calling the group next above 

 the species, a genus. But to a quinary author, sub-genera 

 are indispensable, as they enable him to dispose of any su- 

 perfluous groups which would otherwise raise the genera of a 

 family above their allotted limits of five or twenty -five." 



Mr. Swainson appears somewhat indignant that the reviewer should 

 have made use of the expression " theoretical notions" in reference to the 

 representative system, and the quinary distribution of animals, &c. : now 

 as on other occasions we have ventured to hint that something of theory was, 

 to a greater or less extent, associated with what Mr. Swainson looks upon 

 as altogether a matter of absolute demonstration, we may in this particular 

 fairly identify ourselves with the sentiments put forward by our reviewer. 



Mr. Swainson's impression that the non-adoption of the views which he 

 advocates, arises from our utter incapability of understanding them, is, in a 

 great measure, perfectly true ; and if this incapability depend upon our li- 

 mited acquaintance with zoological facts, it is some consolation to bear in 

 mind, how many naturalists there are whose scientific reputation is of an or- 

 der far beyond that which we are ever likely to attain, and who yet must be 

 placed in the same list of ignoramuses as ourselves, if the comprehension of 

 the natural system, as evolved by Mr. Swainson, is to be the test of a pro- 

 found insight into the science of Zoology. 



