219 



fluence the mode of flight, as instanced by the Swift, Swallow, and 

 Martm, the Tits and the \Vagtails, the Starlings and Partridges. 

 it will probably be found, when this matter is more fully investi- 

 gatecl, that ai soanng birds, and those that remaiu stationary ia 

 the air for a short time, have hollovv humeri, as theFalcon and Sky- 

 lark. lt wll be interestmg also to observe the influence of climate 

 as regards the presence of air in the bones. 



If we look to the form and length of the bones of the wing, how 

 aitterent are they in birds possessing almost equal powers of flight ' 

 1 ake this example before me, the wing of the Swift and of the Marsh 

 Uarner. The length of the bones of the former is :— humerus 

 4 hnes ; cubitus 8 lines ; metacarpus, 8 lines ; phalanges, 4 lines • 

 totai 2 mches ; longest primary feather, 5^ inches. Totai leneth of 

 ^»ig. 7į inches. ° 



Inthe Marsh Harrier the humerus is 4 inches in length ; cubitus 

 4į- inches; metacarpus, 2į inches; phalanges, 1 inch ; and pollex! 

 jotaninch; the longest primary feather, 12 inches; the leneth of 

 the bones, 13 inches. Totai length of wing, 23 inches. 

 .u 'T^^^.'^įffe'-ence in the comparative length of the wing-bones in 

 these birds is very remarkable, and numerous instances of a similar 

 kind might be adduced ; but I am obliged to Umit myself to a few 

 examples. 



From the above Investigation I have come to the subioined con- 

 clnsions : — •* 



• l^'*i ^^^^ ™ *^^ majority of British birds no air-cavities connected 

 with the lungs are present in the bones. 



?^^^y: ^^^^ t^® presence of air in the bones is not necessary for 



switt and long-contmued flight, as instanced especially by the GuUs 



Šnipes, Swallows and Martins. ' 



3rdly. That in no bird that I have examined was air found in 



the bones of the extremities beyond the himeri &nd femora. 



^J' PS'^^n^'*''^^.'^ "" °^'* ^^ ^""^ ^•^'^^d ^" J""e lašt in the eastern 

 part ot buffolk, which he believed to be that of the Great Grey 

 bhrike {Lamus excubitor). It was placed in a thick hawthorn fence 

 about 1 2 feet from the ground. upon a large forked branch It was 

 composed chiefly of dried grass and a little moss on the exterior 

 the hnuig of short grass ; no horsehair nor clay was present • the 

 form rather shallow, and the size about that of the Missel Th'rush 

 {T. viscivorus), the diameter 6 inches, the greatest depth from the 

 nm 4 inches ; from the top of the dome next described to the bottom 

 of the nešt 9^ inches. It was closely domed over with twifrs vary- 

 ing in length from 8 to 12 inches, a small hole being left in^the rim 

 lor the entrance of the bird. The nešt resembled that of the Mao-pie 

 (P. caudata) in miniature, but, as before stated, no clay eutered 

 mto its composition. 



Dr. Crisp was inclined to think that this was the deserted and 

 unfinished nešt of the Grey Shrike, as two birds of the colour of a 

 Jay were seen about the spot early in the spring bv a person well 



