Zoological Society. 57 



India and China. The second species, RhynchcEa picta, he had re- 

 ceived from Africa as well as from India and China. 



Mr. Vigors called the attention of the Committee to the Frigate- 

 bird (Tackypefes AquiluSyVieUl.), and dwelt upon those peculiarities 

 of its organization which point out its station in the series of na- 

 tural affinities that connect the orders of birds. Although it possesses 

 the webbed feet which constitute the technical character of the Na- 

 tatorial Order, the weakness of its legs and their complete covering 

 of feathers preclude it from employing these members in the same 

 manner as the typical groups of the Swimming Birds ; while on the 

 other hand its great powers of wing and tail adapt it for powerful 

 and long-continued flight, and evidently connect it with the Rap- 

 torial Order, which it also resembles in its manner of taking its 

 food. It is in fact rather an inhabitant of the air than of the water : 

 and it has been believed that it derives support during its unlimited 

 flights not merely from the strength and expansion of its wings and 

 the singular mechanism of its tail, but also from the buoyant nature 

 of the inflated sac beneath its throat. A proof of the correctness of 

 the opinion that this pouch is really an air-sac, and that it is filled 

 with air, which passing through the bones becomes rarified and ca- 

 pable of imparting a high degree of buoyanc)^ has recently been 

 obtained from the anatomical notes made by Mr. Collie, late Sur- 

 geon of H..M.S. Blossom, who accompanied Captain Beechey in 

 liis voyage to Behring's Straits; notes which will shortlj' be pub- 

 lished in illustration of the natural history of that expedition. " The 

 pouch beneath the throat of this bird," says Mr. Collie, "is of a 

 yellowish red colour, and when di.stended, the feathers on its upper 

 and posterior surface are separated to some distance from each 

 other, and exhibit very distinctly the quincuncial order in which 

 they are implanted. On first looking at this pouch, I was a little 

 surprised at finding that it did not communicate with the mouth or 

 fauces in any way that I could perceive. I succeeded in inflating 

 it only by long and forcibly blowing into the trachea. I desired the 

 man who had the skinning of the specimens brought on board to 

 inflate the [)ouch before commencing the skinning, and to let me 

 know when he had advanced to the shoulders. He however dis- 

 located the shoulder-joint first, when the distended pouch imme- 

 diately collapsed. The trachea had been tied. As soon as I was 

 informed of this, I had little doubt that the pouch had been in- 

 flated from the lungs ; and on observing two wide oi)cnings, one 

 anterior to the humeral articulating face of the scapula, the other 

 the usual opening of the joint, I hesitated not to infer that it was 

 tiirough the first of tliese the air had passed in, and that the dislo- 

 cating of the joint, by which its capsular ligament was torn, had 

 allowed the air to escape at the opening which corresponds to that 

 on the head of the humerus, and which immediately leads, as well 

 as the other just mentioned, into the centre of the scapula. I now 

 opened the trachea immediately before the .strrnuni, and again 

 attempted inflation from that part, but in vain. 1 tried it also, but 

 with no butter success, from thr larynx. I next examined with the 



A''.^. Vol. 10. No. 55. J?//y 18;>1. I blowpipe 



