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Show 746 MR. J. WOOD-MASON O N T H E [June 18, but rich, purring call which, with breast puffed out, it was uttering- a call perceptible to the hand no less than to the ear. I at once recognized the smaller and less conspicuously coloured birds as specimens of one sex ; and there seemed very little doubt, from its perfect correspondence in structure and general similarity in plumage, that the larger and handsomer one was an individual of the other sex of the Indian Painted Snipe (Bhynchcea capensis, sive bengalensis); but which of the two was the female and which the male, it must be confessed, I was at the time ignorant. In order that I might be enabled to determine the precise relation of the two forms to one another, and to ascertain whether any structural differences in their vocal organs accompanied the observed differences in their vocal powers-merely that I might know these facts of m y own knowledge, certainly without the slightest hope or thought that I should be able, from such a cursory examination as alone I could give to it, to glean any thing new about so common an animal, I purchased a pair of the species. Before killing the birds for examination, I referred to Darwin's ' Descent of Man'1; and what I read therein served but to increase my interest in the matter; for I soon saw that I had it in my power to corroborate or to contradict a statement which had been made about the trachea of this very species-the very part, curiously enough, the sounds issuing from which had drawn m y attention to the bird. It is well known that in many birds the windpipe, instead of taking a straight course from the rima glottidis through the interclavicular membrane to the point where it bifurcates to form the bronchi, is bent upon itself or convoluted, and that often to an extraordinary extent. The position of such flexures is very variable : " they may lie outside the thorax under the integument (as in Tetrao urogallus, some species of Crax and Penelope, and, I may add, the Manucodias2 and the Rhynchseas), in the cavity of the thorax (as in some Spoonbills), on the exterior of the sternum (as in some Swans and Cranes), or even in a sort of cup formed by the median process of the furcula (as in a species of Guinea-fowl) "3. The increase in the length of the tracheal column implied by these convolutions, and other modifications of the windpipe, such as the swollen tympanum of Ducks and Geese, the air-sac of the Emu, may be dependent wholly upon sex ; and the males may have the trachea more or less looped or more complex, whilst the females have it straight or simple, or only partially so, in which case the flexure or other modification may be more marked in males than in females. But however this may be, it is a general rule that whenever "the trachea differs in structure in the two sexes it is more developed and complex in the male than in the female"4; and it is a fact familiar to all that in the vast majority of instances it is the male which, in point of richness of plumage, vocal powers, and ornamental appendages, is the more highly 1 Op. cit. p. 476. 2 'Nature,' vol. xv. p. 127. 3 Huxley, 'Anatomy of Vertebrated Animals,' p. 315. 4 ' Descent of Man,' /. supra cit. |