1866.] 



Dr. John Davy on the Bones of Birds* 



303 



in water ; they contained no air, but a soft marrow, of a blood-red colour. 

 The bones were very vascular, and were easily cut. 



2. Of another, shot on the 22nd of June, when capable of flight, 

 though the quill-feathers of its wings were only partially hollow, its weight 

 5113 grs., the humeri sank in water in a perpendicular position. Of one 

 which was examined, its inferior two-thirds were found full of a reddish 

 marrow, its superior one-third of air. The proportion of oil seemed 

 greatest in the distal part of the marrow. The bones were less vascula 

 than those of the preceding, and of greater firmness. 



3. Of a third, shot on the 23rd of June, then weighing 4982 grs., 

 which, judging from the state of its feathers, its bursa Fabricii, ovary, and 

 oviduct, had been hatched in the spring, the humeri were full of air 

 without a vestige of marrow *. 



VIII. Common Crow. — Of one shot on the 1st of June, then weighing 

 5402 grs., its quill-feathers not fully formed, the humeri sank in water, 

 and contained only marrow. 



2. Of another shot on the 21st of June, weighing 6533 grs., capable of 

 flight, the humeri contained air. The lining membrane was very vascular. 



IX. Of the Tawny Owl. — Of a young one, examined on the 21st of 

 June, then weighing 4796 grs., its quill-feathers not fully formed, the 

 humeri contained a very red marrow, and were entirely destitute of air. 



2. Of one of uncertain but mature age, judging from its general appear- 

 ance, and which weighed on the 8th of April 5776 grs., the humeri were 

 full of air. There was also air in the scapular arch, and partially in the 

 furcula, its proximate portion. 



X. Of the Sparrow-hawk. — Of a young one, which on the 31st of 

 July weighed 3686 grs., its sternum then only partially ossified, still 

 flexible, the humeri were for the most part hollow ; the little marrow they 

 contained was confined to their distal portion. The same remark was 

 applicable to the scapular arch. The femora contained even less marrow 

 than the humeri ; they were very nearly full of air. 



XI. Of the Buzzard. — Of a young one taken from its nest on the 

 10th of June, when supposed to be about a fortnight old, then weighing 

 5293 grs., the quill- feathers of wings only sprouting, the bones generally 

 were very vascular ; the humeri and femora sank in water. Their ossifi- 

 cation was much advanced, but the sternum was still cartilaginous. After 

 drying, all the bones floated in water. The humeri and femora, now laid 

 open, were found to contain a red matter lining but not filling the cavities, 

 suggestive of its having been, in its moist state, a fluid or a semifluid. In 

 this, its dried state, it was of a firm consistence. After soaking in water and 

 trituration, it formed an emulsion, which, as seen under the microscope, was 

 found to contain oil-globules and particles of different kinds. Digested and 



* This bird, like most rooks, was infested with parasites, lice. They were plentiful 

 even in the cavity of the wing quill-feathers. According to Dr. Gray, F.E.S., to whom 

 I sent one, and who kindly gave me its name, it is a Decophorus {D, atrattcs). 



