13 



Common Gull. L. canus. Swallow. H. rustica. 



Black-headed Gull. L. ridibun- Sand Martin. H. riparia. 



dus. Goat-sucker. C. Europceus. 



Herring Gull. L. argentatus. Chaffinch. F. ccelebs. 



Great Black-backed Gull. L. Yellow-hammer. E. citrinella. 



marinus. Sparrow. F. domestica. 



Bazor Bill. A. Torda. Wheat-ear. 8. cenanthe. 



Puffin. F. arctica. Wren, Common. T. Europceus. 



Red-throated Diver. C. septen- Wren, Crested. R. auricapillus. 



trionalis. Bobin. 8. rubicula. 



Moor Hen. G. chloropus. Blackbird. T. merula. 



Coot. F. atra. Thrush. T. musicus. 



Curlew. N. arquata. Fieldfare. T. pilaris. 



Godwit. L. melanura. Bed-wing. T. iliacus. 



Dotterel. C. morinellus. Missel Thrush. E. viscivorus. 



Common Snipe. S. gallinago. Starling. S. vidgaris. 



Jack Snipe. 8. gallinula. Hedge Sparrow. A. modidaris. 



Sanderling. A. vulgaris. Little Creeper. C.familiaris. 



Water Ousel. C. aquaticus. Wood Lark. A. arbor ea. 



Swift, Common. H. apus. Oyster-catcher. H. ostralegus. 

 House Martin. H. urbica. 



I have mislaid the notes of my dissections of many other British 

 birds, and as I do not like to trust to memory, I will reserve these 

 for the concluding part of my paper. 



' Of the above fifty-two birds, the first only had many of the bones 

 permeated with air ; the next thirteen on the list had the humeri 

 only hollow, and among these it will be observed that there are many 

 of short flight. Of the remaining thirty-eight none of them had 

 marrow in the femora or humeri, and judging from a few that were 

 examined (the snipe, e. g.), none of the bones contained air. The 

 last list includes some birds, as the swift, martin and swallow, that 

 are longer on the wing and probably of swifter flight than any of 

 the feathered creation. 



. By way of testing more accurately the correctness of my conclu- 

 sions, I performed the following experiments : — I introduced a blow- 

 pipe into the trachea of a common duck, a cock, a French partridge, 

 an English partridge, and a snipe ; I opened the humeri and femora 

 of all, and placed the dead birds under water ; I then inflated the 

 lungs and air-cells in the chest and abdomen, the size of the birds 

 being greatly increased by the inflation. In the cock the air escaped 

 freely from the aperture in the humerus ; but in the other birds no 

 air was present. I then removed the humerus and femur at the 

 upper joint, but still no air escaped on inflation. As I have stated 

 before, all these, birds, with the exception of the snipe, had hollow 

 humeri, but none of them had air in the thigh-bones ; these experi- 

 ments, however, require repetition on a larger scale. 



In my next paper I purpose describing the air-sacs in the thoracic 

 and abdominal cavities of birds ; the method by which air is ad- 

 mitted to the hollow bones ; and the flight of birds in relation to these 

 matters. 



