300 



Dr. John Davy on the Bones of Birds. [Dec. 6, 



2. K chicken twenty-eight days old, reckoning from the time of hatching, 

 was found dead on the 12th of January ; during the preceding night there 

 had been a severe frost. It weighed 10,275 grs. ; one of its humeri in its 

 moist state weighed 2*5 grs. ; one of its femora 8 grs. In each of them 

 a soft red medullary matter was detected, which, like the preceding, was 

 composed of oil-globules, blood-corpuscles, and smaller colourless corpuscles 

 or cells. The contents of the ulna and clavicular arch were similar, but 

 in the latter the quantity of medullary matter was very minute. 



3. Of a pullet three months old, which had been hatched on the 6th of 

 April, and weighed, when examined, two pounds, the humeri thoroughly 

 ossified, sank in water. From one of them, opened under water, a few air- 

 bubbles only escaped, which came from its superior extremity. The canal of 

 the bone, excepting the small portion from which the air proceeded, was full 

 of red marrow of the usual appearance of medullary tissue, and with similar 

 contents. A communication was found to exist by the air- foramen between 

 the cancellated structure towards the head of the bone and the lung, 

 through the adjoining air-sac. 



4. Of another pullet of the same brood, but of more advanced growth, 

 which, though three days younger when examined, weighed two pounds 

 and three-quarters, the humeri sank in water, but in sinking maintained a 

 perpendicular position. One of them laid open was found to contain in its 

 inferior portion, to the extent of '7 inch, marrow ; in its superior, to the 

 extent of 1 "8 inch, air. 



5. Of a pullet three months and eleven days old, which had been 

 hatched on the 28th of May, the humeri floated in water. In one of them, 

 laid open, a small portion of marrow was found in the cancellated structure 

 of its distal extremity ; and in this portion a conspicuous blood-vessel 

 terminated, 



6. Of a cock five months old, which weighed five pounds, the testes 

 large, and abounding in sperm-cells and spermatozoa, the humeri contained 

 only air. 



II. Of the Partridge. — Of one shot on the 1st of September, which 

 weighed 4136 grs., the humeri and femora sank in water; in sinking the 

 distal extremity of the former reached the bottom first. From one of these, 

 opened under water, a very little air escaped. The lining membrane was 

 very vascular, and the lower one-fourth of the canal was full of blood of 

 a dark colour, contained apparently in varicose vessels. Under the micro- 

 scope, no oil-globules were distinguishable in the blood, only blood-cor- 

 puscles ; nor in any part of the cavity were there found any remains of 

 marrow. 



2c Of another, shot on the same day, which weighed 5226 grs., the 

 humeri swam in water, the femora sank. Air only was found in the 

 former. On the lining membrane there were two or three delicate vessels 

 containing florid blood. The femora were full of a reddish marrow. 



3. Of another, shot on the 19th of October, which weighed 5432 grs.. 



