where the bird had rolled, they would be laid in the midst of such a collection, which would, of course, be increased, were the female bird to act in a similar way, and in the same place. Nor is this last so unlikely, for in many species both sexes indulge in the same odd postures and contortions during the breeding season.
All the above suppositions have been suggested to me by what I have actually seen birds do whilst under the influence of strong sexual excitement, and, though I am ready to admit that the foundation of fact may have been slight in comparison with the superstructure of theory raised upon it, yet there can be no harm in a provisional hypothesis; and, besides, what is the use of staring at facts with eyes that have "no speculation" in them? For myself, I shall always strive to see the causes of things with the things; nor do I know of anything worse that can happen to one by this method than to have it pronounced on all hands that one's theories are "less happy" than one's records of facts, a dictum which, till argument is met by argument, one may take to mean something like this—"We are equal to a fact or two, but theories make our heads spin round."
(To be continued.)
"The nest.—...."made by the pair together. The cock goes down on to his breast, scraping or kicking the sand out backwards with his feet, &e. The hen stands by, often fluttering and clicking her wings, and helps by picking up the sand with her beak, and dropping it irregularly near the edge of the growing depression.
"The little embankment round the nest.... The sitting bird, while on the nest, sometimes pecks the sand up with its beak nearly as far from the nest as it can reach, and drops it around the body. A little embankment is thus gradually formed.... The formation.... is aided by a peculiar habit of the birds. When the bird on the nest is much excited (as by the approach of other birds or people) it snaps up the sand spasmodically without rising from the nest, and without lifting its head more than a few inches from the ground. The bank is raised by such sand as falls inward. The original nest is merely a shallow depression."
Remarks follow on the use of the bank, which has become a part—and an important part—of the nest. We, however, are concerned with the origin both of it and the depression. It seems clear, from the account, that the former is sometimes made, or added to, when there can hardly be an intention of making it: whilst, to make the latter, the cock assumes the attitude of sexual frenzy (described in the same paper), which is one, as it seems to me, hardly necessary for mere scratching alone. Had the latter, however, grown out of the former, we can well understand the characteristic posture being continued. The italics are my own.
