The displays take place in the early hours of the morning, when parties of from a dozen to fifty, of both sexes, meet on some slight knolls where the grass is short. Having duly assembled, the more ardent cocks immediately begin to prepare for the morning revels, the first part of the performance apparently being of a comparatively passive nature—the parade of the air-sacs and the erection of the feathers. Then some “proud cock, in order to complete his triumph, will rush forward at his best speed ... through the midst of the love-sick damsels, pouring out as he goes a booming noise ... which may be heard for at least two miles in the morning air. This sound is by no means harsh or unpleasant. When standing in the open prairie at early dawn listening to hundreds of different voices pitched in different keys, coming from every direction and from various distances, the listener is rather soothed than excited. “Every few minutes this display is repeated. I have seen not only one, but more than twenty cocks going through this funny operation at once; but then they seem careful not to run against each other, for they have not yet got to the fighting point. After a little while the lady birds begin to show an interest in the proceedings by moving about quickly, a few yards at a time, and then standing still a short time. “The party breaks up when the sun is half an hour high, to be repeated the next morning, and every morning for a week or two before all make satisfactory matches. It is towards the latter part of the love-season that the fighting takes place among the cocks, probably by two who have fallen in love with the same sweetheart....” There is much that is extremely interesting in this account and a little that seems to have been misinterpreted. The fact that these antics are repeated during many days until at last the females are moved to display some interest is just what we should expect if this demonstrative behaviour on the part of the males acts, as we believe, as an aphrodisiac. And that actual fighting occurs is highly probable, but there can be no doubt that in such case the whole aspect of the bird must be changed, for anything in the nature of fighting with the delicate air-sacs inflated would greatly endanger the most important aid to success in achieving this object which these birds possess. [Illustration: Plate 20. _Photo from The Museum of Natural History, New York._ THE LOVE-MAKING OF THE PRAIRIE HEN. During the “display” large, yellow, air-sacs in the neck are inflated. The bird in the foreground shows one of these, and the ornamental feather frill, very clearly. [Face page 110.]