28 THE NATURALIST’S GUIDE. 
‘these gently with the point of the knife, and beneath them 
will be seen the sexual organs, which are fully illustrated 
fin the following diagrams. 
’ Puare V., Fig. 2, isan adult male (g) in the brecding 
season. 1 shows the position of the lungs, 2 the pecu- 
liar yellowish glands, — in some birds bright yellow, in the 
‘present case — that of & song sparrow (Mfelogpiza melodin, 
“Baird) — they are yellowish white, which; being present 
in both sexes, if not examined closely, may he easily mis- 
‘taken, in the young female, for the: testicles of the male. 
'3, 3, are the testicles, much enlarged in this, the breeding 
‘season. The sex of a bird in this: aage is easily deter- 
sey 
Prats VL, Fig. 1, is a young male (3) {ni the young: 
of-the-year plumage. The figures refer to the same parts 
as explained in the preceding. It will be perceived. that 
the testicles (3) are much smaller. At different seasons. 
the testicles vary ‘in size between this and the preceding. 
In some birds they are elongated, and black iu color, 
as in the Herons; but they always occupy the same posi- 
tions so nearly as tobe readily distinguished. The pcvi- 
liar white glands (2) are in 'this‘instance very promincut, 
but they are readily known in-all birds by their being ‘fit, 
while the testicles are always spherical. : + 
Puate V., Fig. 1. This -is“arrsadnlt' fethale (9) in‘ the 
breeding season. “1, I, are the same peculiar glands ‘observed 
in the males; 2 is the ovary;'a mass of spheres at ‘this 
season quite yellow and prominent} 3 is' the. oviduct, ur 
eve-passage, much enlarged in ‘the present case, as it always 
is during the breeding season,’ when -it' assumes a -thick, 
swollen appearance, while at: other-times it is transhiccnt, 
much smaller, and resembles a aes whitish line, >1ot 
readily perceived. a a 
Puate VL, Fig. 2," is a young-of- the: -year fei in du- 
tumn. 1, 1, the same white.glands that at this stage of ‘the 
