94 MISCELLANEOUS PARTICULARS. 

out; when producing eggs, its appearance is unmistakable. 
Both testis and ovary may further be recognized by a thread | 
leading to the end of the lower bowels—in one case the sperm- 
duct, in the other the oviduct; the latter is usually much the 
more conspicuous, as it at times transmits the perfect egg. 
There is no difficulty in reaching the site of these organs. Lay 
the bird on the right side, its belly toward you: cut with the ) 
scissors through the belly-walls diagonally from anus to the a 
root of the last rib—or further, snipping across a few of the 
lower ribs, if these continue far down, as they do in a loon for — 
instance. Press the whole mass of intestines aside collectively, a 
and you at once see to the small of the back. ‘There you ob- a 
serve the kidneys—large, lobular, dark reddish masses moulded 
into the concavity of the sacrum (or back middle bone of the 
pelvis) and on their surface, towards their fore end, lie testes 
or ovary, as just described. The only precaution required is, 
not to mistake for testicles a pair of small bodies capping the 
kidneys. These are the adrenals or ‘‘ supra-renal capsules ”— 
organs whose function is unknown, but with which at any rate 
we have nothing to do in this connection. They occur in both 
sexes, and if the testicles are not immediately seen, or the 
ovary not at once recognized, they might easily be mistaken 
for testicles. Observe that instead of lying in front, they 
cap the kidneys; that they are usually yellowish instead of 
opaque whitish ; and that they have not the firm, smooth, reg- 
ular sphericity of the testicles. The sex determined, use the 
sign ¢ or 9 to designate it, as already explained. In the very 
rare cases of impotence or sterility among birds, of course no 
organs will be observed; but Ishould dislike to become respon- 
sible for such labelling without very careful examination. The 
organs of a small bird out of the breeding season are never 
conspicuous, but may always be found on close scrutiny, unless 
the parts are disintegrated by a shot. 
$47. RECOGNITION OF AGE is a matter of ornithological ex- 
perience requiring in many or most cases great familiarity with 
birds for its even approximate accomplishment. There are, 

