When my informant first observed the light, he was a hundred and fifty feet away, and while slowly creeping toward it saw it disappear four times, the intervals between the disappearance and re-appearance being long enough for him to count twenty at a moderate rate; from which he assumed that the bird has the light more or less under control, and governs it by raising or depressing the feathers that cover the powder-down patches. When he fired at the bird, the light on the breast was so intense that he distinctly saw the sight of his gun against it, and he describes its brilliancy as comparable to that of a lantern or hand-lamp. He did not notice a reflection upon the water, as he was some distance away, and in a recumbent position, which rendered it impossible. The bird fell where it was standing, in six inches of water; and taking it by the wings, he threw it upon the shore, noticing and watching the three phosphorescent spots, one in front, and one on each side of the hips, between the hips and the tail. The bird died slowly, _the light gradually dying out, and disappearing entirely with death_; a fact which I consider to be of the greatest interest, showing that the phosphorescence is not an accidental occurrence, depending upon a favorable condition of the greasy powder-down patches, or associated entirely with their decomposition, but is essentially due to some physiological action, and dependent upon the life of the bird; and the areas of the powder-down patches may be considered true photogenic structures. The bird shot and examined by Mr. Worrall was known to him as the blue crane, and I assume from his description that it is the _Ardea cærulea_. The other birds in which the light was observed were night herons. The light was in the so-called powder-down patches, which form a characteristic feature of the herons, and doubtless serve the same purpose, as a lure, in all. In a night heron, which I recently obtained from a valley among the foothills of the Sierra Madre range, there were three of those patches, and any heron will show them. One is directly in front upon the breast, while the other two are upon each side, midway between the base of the tail and the upper portion of the thigh-bone. They are not visible unless the feathers which cover these portions are brushed aside, when a mass of oily small plumes are seen, of a decided yellow hue, growing closely together, and about two inches in length. A yellow powder will be found profusely mixed among them, and is due to their barbed tips breaking off as fast as they develop.