INSESSORIAL BIRDS. 231 



of which intention I have selected my present subject. Persuaded 

 that the group of Scansorial Birds is too well marked and important 

 to rank only as a sub-order of Insessores, and in fact has as good a 

 claim as Eaptores to be accounted an order, I without hesitation 

 assign to it that position ; but I cannot follow Dr. George Gray 

 in giving the same distinction to the families of Colnmbidoe and 

 Struthionidce : I have then before me six Orders of the Class Ates, 

 one of which, the Perching-birds, called Insessores, exhibits the spe- 

 cial bird type most completely, and is vastly more numerous than 

 any of the others. In accordance with views of the classification of 

 the animal kingdom which I have on other occasions endeavoured to 

 explain, defend and apply, and which amount to an attempt to revive 

 with considerable modifications the ideas of McLeay and Swainson, 

 I place the Insessores in the centre, with the five other orders placed 

 around them, and I am led to expect to find five sub-orders or great 

 sections of Insessores, manifesting certain analogies with the other 

 five orders. The sub-orders of Cuvier, founded on the beak and 

 feet, at once invite attentive examination, and we cannot fail to 

 observe that the Dentirosfres represent the Raptores ; the Conirostres 

 the Rasores ; the Tenuirostres the Grallatores [picking out food from 

 obscure places, with an elongated, generally pointed beak, and in a 

 manner sometimes almost suctorial], whilst the Fissirostres [darting 

 at their prey whilst moving in their appropriate element] represent 

 the Natatores. If, however, we should be tempted by these analo- 

 gies to compare Cuvier's remaining sub-order Syndactyli with the 

 Scansores, we are encountered by difficulties seemingly insurmount- 

 able. I was at first disposed to try the effect of this method, but 

 the more I put it to the test, the more evident it became that it 

 completely failed. Still, not readily abandoning principles which 

 seemed to give such. beautiful results in a great variety of instances. 

 I returned again and again to the inquiries how the Syndactyli of 

 Cuvier ought to be disposed of, and whether among Insessorial 

 birds, without disturbing the other sub-orders, there really exists 

 any group exhibiting an analogy with the order Scansores. These 

 questions soon brought before me the proper limits of the sub-order 

 Fissirostres, and having satisfied my own mind by a scheme which, 

 as far as I know, is novel, I submit it to the candid judgment of my 

 fellow-students of nature with no other desire than that it may be 

 considered and fairly judged. It could not fail to be observed that, 

 great as is the authority of Cuvier, and very generally as his other 



