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 Jan., 1919 PUBLICATIONS REVIEWED 45. ern hmisphere. ". . . Migration is sim- ply an exodus, followed by a return move- ment to breeding grounds." ". Bird migration is the adjustment of the bird pop- ulation of the world to the seasons ., the evolution of the seasons being the re- mote cause of bird migration." The more speculative portion of Loomis's paper, for example as to how migrating birds find their way, are stimulative, and will always need to be taken account of by future students in the field, but they leave the reader in dark- ness at many turns. We note, in this con- nection, that John B. Watsoh's conclusions are discounted. Loomis can see no good rea- son for ascribing to birds a sixth sense by which they. can find their way. They are guided solely, in his opinion, by ordinary faculties intensified, plus an "innate desire to travel." An admittedly weak place in this guidance 'theory concerns the return- migration of birds nesting on remote oceanic islands. The detailed descriptions of molts and plumages, based in many cases upon long se- ries of specimens, constitute perhaps the most important feature of the paper. We are quite convinced that Loomis is right in placing.in synonymy a number of names, the original characterizations accompanying the proposal of which include only points of col- or just such as is demonstrated in available material to be due to age, fading, or loss of "bloom". No one who in the future attempts to deal systematically with the Tubinares can allow himself to overlook these import- ant factors; and to become thoroughly famil- iar with them requires a great amount of close study and an exercise of mature judg.. ment. , In this connection, Loomis lays great stress on what appears to him to be in this order of birds a relatively very common state of double coloration, or "dichromat- ism". In certain cases he is inclined to look upon dichromatism as subject to geographic factors, so that a light phase of a given spe- cies might predominate or occur exclusively in one area, and a dark phase of the same species in another. Here we are tempted to believe that the dichromatism idea has be- come confused with that of true geographic variation, the latter leading to the origin of new Species. Dichromatism undoubtedly does exist in certain tubinarine biyds, but there is a chance that Loomis has inferred its existence in cases where adequate ma- terial is still lacking to completely establish the fact. Mr. Loomis's special method of handling geographic variation leads him to place un- der the synonymy of Oceano(lroma leucorhoa no less than five current names of petrels, namely socorroensis, kaedingi, monorhis, beldingi, and beali. This case illustrates his tenet that "the subspecies theory" is "dis- carded as a theory that has outlived its use- fulness." In other words only full species are given systematic recognition, the criterion of intergradation, as here specially applied, serving as the basis of exclusion. Geographic variation is h.andled as of coordinate import- ance with age, sexual and seasonal varia- tion. It is as if the process of evolution itself had been denied! On the other hand we cannot but heartily commend Loomis's conservative stand in re- gard to the recognition of genera. The fu- tility of repeated sub.division of genera down to the only logical limit, the one-species ge- nus, is well set forth. There can in our mind be little well-grounded defense of the principle lately put into practice by Mathews and others whereby it is concluded that two species occupying the same area must ?acto belong to two separate genera. Cooper's California record of the Yellow- nosed Albatross ( Thalassogeron culminatus ) on the basis of a skull found on the sea- beach near San Francisco is corroborated by Mr. Loomis. The skull, with bill largely in- tact, was carefully examined previous to its destruction in the fire of 1906. The species thus becomes re-instated on our regular list of California birds, it having heretofore re- posed among the hypotheticals. Cooper's record of the Giant Fulmar from Monterey is not, however, credited Several' tubinarine birds are recorded from the high seas some hundreds of miles off the coast of California whose names do not appear on our state list nor even on the North American list. Of course the limits of a state with a sea coast can only be set at a greater or less distance offshore in arbi- trary fashion, but it would seem to the un- dersigned that they should not extend be- yond say one hundred miles' outside the headlands or outermost islands. It is per- haps a somewhat different matter as regards inclusion in the North American list. The care displayed throughout in gram- matical construction, spelling and final proof-reading, has resulted in a production well-nigh above criticism from these stand- points. Indeed, it may be stated with some assurance that no ornithological paper has appeared in years so free from typographical