174 REPORT — 1844. 



these original generalizations. The classification followed in this M'ork is 

 very complex, and in some of its portions very artificial, the genera being 

 arrived at through a numerous and irregular series of successive subdivisions, 

 founded in many cases upon arbitrary and isolated characters. Perhaps the 

 most valuable portions of the work are the generic definitions, which are 

 worked out with greater care than the specific descriptions. 



Professor Eichwald gave a synopsis of the class of birds with brief de- 

 scriptions of the Russian species in his ' Zoologia Specialis,' Wilna, 1831. 

 Prefixed to it is a good general resume of the characters, external and inter- 

 nal, of the ornithic class. 



The arrangement of birds proposed by Wagler (Systema Araphibiorum) 

 and by Nitzsch (Pterylographia) have not yet fallen under my inspection. 



In 1831 the Prince C. L. Bonaparte published his ' Saggio di una Distri- 

 buzione Metodica degli Animali Vertebrati,' exhibiting a sj'stem of ornitho- 

 logy, of which he had previously given a sketch in the ' Annals of the Lyceum 

 of New York,' vol. ii. 1828. As this arrangement seems in its main features 

 to approach more nearly to the system of nature than any contemporary me- 

 thod, it will be worth while to enter into some detail respecting it. The au- 

 thor divides the class of birds in the first instance into two great groups or 

 subclasses, Insessores or perchers, and Grallatores or walkers, the first in- 

 cluding the orders Accipitres and Passeres, and the second the Gallina;, 

 Grallce, and Anseres. Most other zoologists, from the time of Linnseus to 

 the present day, unconsciously prejudiced by the size, rapacious habits and 

 celebrity of the birds of prey, have attached too much importance to their 

 characters, and have made them into one of the primary divisions of the class 

 Aves. But on an unbiassed estimate of their characters it will appear that 

 the Accipitres form merely a division of the great group of Perchers, agree- 

 ing with them in all essential points of organization, and not differing more 

 than some of the subdivisions of the perchers do from each other. It was 

 therefore a justifiable act to lower the Accipitres from the lofty place which 

 they had long occupied, and to subordinate them to the Insessores. I even 

 think that the learned author might have gone a step further, by making his 

 subclass Insessores to consist of one order, Passeres only, while the Accipi- 

 tres would stand on a level with his Scmisores and Ambulaiores, as a tribe or 

 subdivision of Passeres. 



The primary division of all birds into perchers and vmlkers, though pro- 

 fessedly based on the position and development of so unimportant an organ 

 as the hind-toe, and therefore liable at first sight to be termed arbitrary and 

 artificial, is yet confirmed by so many other important and coextensive cha- 

 racters to which the structure of the hind-toe serves as an external indication, 

 that we cannot doubt of this arrangement being conformable to nature. No 

 person acquainted with the difficulty of defining the larger groups of zoology, 

 will, of course, expect logical exactness in the application of these or of any 

 other set of characters to the orders of ornithology. But allowing for such 

 exceptions as occur in all zoological generalizations, it is certain that by this 

 arrangement two great groups of birds are pointed out, the one arboreal, 

 with perching feet, monogamous, constructing elaborate nests, and rearing a 

 blind, naked, and helpless offspring ; while the otiiers are terrestrial, with am- 

 bulatory feet, frequently polygamous, displaying no skill in the form of their 

 nests, and producing young which are clothed and able to see and to run as 

 soon as hatched. 



The classification of Vertebrata, which Prince C. L. Bonaparte sketched out 

 in the above work, is further developed in a paper M'hich he communicated to 



