70 THE CONDOR Vol. XVIII We venture to hope, also, that the acquisition of really cosmopolitan mate- rial may enable us to shed some light upon the unsolved problem of the causes of variation in the eggs of the Passerinc forms. We conceive this in itself to be a not unworthy task. Besides these phylogenetic matters, a score of lesser problems, all of strictly scientific import, group themselves under the head of comparative o51ogy proper. For example: The mechanics and chemistry of l?igmentation. The effect of climate Ul?On color--the l?rogressive darkening of northern eggs; the reduction of Sl?otting in desert-]?aunt?ng Sloeties. Homol?lasy, or the tendency to similarity in eggs, indel?endent of that of the par- ents. Degeneration of l?igment. Albinism and reversion to white, gradual or sudden. "Economy". Persistence of and reversion to l?rimitive characters. The range of individual, Sl?ecific, and generic variation. The relation of number and size in eggs to food-quality or abundance. The relation of number and size to the forage radius of the l?arent. The relation of bulk to l?recocity, or l?rel?aredness in the chick. The effects of isolation, l?ersecution, coml?etition, degeneration and senescence. "Psychological" control of the rel?roductive cycle. Does the high coloring of eggs in the Passerinc forms evidence a dawning esthetic interest in the l?arents? These and a dozen other lines of inquiry of equal moment suggest them- selves to the student of comparative oSlogy. We hold it, then, to be well worth while to assemble with painstaking care material adequate for the solution of these problems. Those pseUdo-scientists who affect to despise the opportunity for research offered by a comparative study of birds' eggs are simply airing their own ignorance. But of course these problems connect themselves with a vastly wider realm of inquiry. The egg is merely the focal point about which gather the highly complicated and indubitably fascinating interests of the reproductive cycle. Although named after this focal point, it is farthest from the purpose of the Museum of Comparative O51ogy to confine itself 'to a study of the egg alone. The nest is of at least equal, perhaps of greater, interest. AlthOugh its phylo- genetic value may be small, there is nothing else in natur? so eloquent, so con- cretely revealing of the hidden life, of "animal psychology", as the nest of a bird. It is an epitome of history, an aspiration, of intelligence, and of all besides that goes to make up the charm of a living bird. It is to our discredit that the study of nidology has been so much neglected in America,--for no better reason, apparently, than that nests "take up a lot of room". This glaring defect in our study apparatus, the Muse'urn of Comparative O51ogy proposes to remedy. Our plans are drafted about the central idea of providing storage space for represen- tative nests of all the world's birds. And here, again, our interest does not stop. Since the higher mauifesta- tions of avian activity group themselves about the reproductive cycle, or, in effect, focus upon the nest and its contents, it would be idle for us to single out the center and neglect the rest. As Terence said, Huma?i nihil a me alienum puto, we can say Aviarii nihil a nobis alienurn putamus, for we hold that nothing which pertains to birds is foreign to our interest. The Museum of Comparative 05]ogy will devote itself to the fullest exploitation of the claims of the bird. Our choice of a title, then, is a matter of emphasis and distinction rather than of exclusion. Study of the bird afield, photography, the recording of data, whether
