This page needs to be proofread.

May, I9o7 ORNITHOLOGY FOR A STUDENT OF EVOLUTIONARY PROBLEMS 69 characterizations similar to those on which is based the classification of crystals and rocks. Form, color, proportions, texture, are these not, after all, the quali- ties upon which the ornithologist--in common with all other zoologists--relies for his classification to well nigh the same extent as does the crystallographer and the petrographer? And yet the bird is a [/z;n? thing; exactly that about it which gives it its interest as compared with the crystal and the rock, quite ignored in its classification! Can anything be more patent, when once you look the situation squarely in the face, than that our biological classifications mztsl sooner or later be put on a broader foundation? Nothing that is ]?a/_/'done is well done. Obviously our sys- tems are not more than half done; for they practically ignore at least half of the nature of the objects classified. Ill would it become me, a peculiarly unworthy member of the Cooper Club, to bolt into your midst with suggestions of new enterprises for the Club. I am not going to do this. Addressing you not as club members, but as a group of wide- awake ornithologists, I am merely going to point out wherein, as I see it, ornithol- ogy has a vantage ground quite its own in which to use such of the new instrn- ments of research as have already proved their efficacy. Wonld it not be practicable thru cooperation to test the nature of so-called outogenic species among West-American birds? It seems to me that a fexv incu- bators, a few capacious but inexpensive out-of-door bird cages and a few compe- tent ornithologists judiciously located in different parts of California would in a few years go a long way toward the final answer to this question. What consider- able difficulty should there be in the way of taking the eggs of some of the bleached- out desert species like thb Le Conte thrasher, the Abert towbee, the desert song sparrow, and the pallid wren-tit, to San Francisco, or Eureka, and rearing the broods to see what effect the new climate would have on the color ? Again wtro knows that the question of natural hybridization among birds might not be successfully attacked by breeding experiments? And what a capital problem this is, more than ever now that unit characters and Mendelian inheritance are among the realities of biology! I can think of no set of facts an interpretation of which would be more illumi- nating than those presented by the supposed hybrids of the two flickers, the golden- shafted and the red-shafted. This problem appears to stand about where it was in 1892. Allen's studies on the distribution of the genus Colaples and the color styles assumed by the "hybrids" between auralus and caj'kr were published in that year. Much as this good work advanced the subject, it left the most critical points as dark as ever. Do these two species actually mate together? If so are all of the offspring of the same pair marked in the same way? Are the hybrids fertile, and if so how are they marked? Do "hybrids" ever come from pure stock mat- ings of either auralus or caret ? Perhaps these birds could not be induced to breed in captivity, but a whole string of such questions might be partly or wholly answered by studies in nature. An ornithologist well trained in general biology ought to be enabled to devote himself to this single question for an indefinite period. During the breeding season he should spend most of his time in the field; and when he could get away from the demands in this quarter, there would be plenty of laboratory and museum work on pigments, embryonic stages, moulting, anatomy etc. Furthermore the possibility of the birds breeding in captivity should be care- fully tested. Pedigree culture, and crossing under control, would tell most could they be applied. No one but an ornithologist, however skilled in the methods of general biology, is equal to such a problem.