MEMOIH 01'’ CAMPER. 
45 
liis excellent discourse on the nature of birds, 
*ut be says iiotliing concerning this extraordinary 
‘“laptation of struct ure. 
'■ Ihere was brought me on the 1st of February 
<71 a great sea-eagle, of which I made a minute 
'^section. Among other parts, I prepared one of 
thigh-bones, chiefly to shew its cavity, and the 
bres which support the bony plate in its interior, 
expected to find marrow, but was disappointed, 
< iscovering notliing but the periosteum, and a large 
and some traces of air. Astonished at this 
peculiarity, I took a sketch of it, and instantly went 
'■e examine tlie skeletons of a common eagle, an ara, 
®ed an owl. I found a great foramen in the upper 
P^‘t of the thigh-bone of the eagle, but no appear- 
etice of one in the other two birds ; but I at the 
®aine time discovered a foramen near the head of the 
8 eat bone of the wing, in the whole of my skele- 
of birds. This was true also with the recent 
ca eagle, and hence the first step of my reasoning ; 
^‘nero is a foramen in the leg bone, and air in it; 
tere is also a foramen in the wing bone, and pro- 
y theie is air in it also, though, as yet, I know 
j / "'^‘cnce it comes. It happened that at this time 
hol^^’ which had just died : I drilled a small 
.. ^ principal bone of its wing; to this I ap- 
th ^ I'lowpipe, and found, to my great delight, 
^ at, in blowing through it, I inflated the whole of 
aif '*^**^’ abdomen ; after this, the 
made its escape by the windpipe. I then re- 
