THE CONDOR Vol. XIII FORMES" (Univ. Calif. Publ. Zool. VI, Decem- bet 4910, ?pp, r.285-312).?Mr.. Henry Chester .Tracy un?te?. the above title adds an unusually i?nportant .contribut/on to both fact and theory relative to.?h.e.g?neral subject of adaptive col- oration. ?: ?he province particularly dealt with is that of so-called directlye markings, which terr0 has been employed in explaining a type .-o[ color.,ation?where .white or light patches are ?,,?con.spicuously contrasted with black or dark .A?re_as. .This theory, of the directlye function ? of eovtrasted markings, has recently been un- -.qualifiedly condemned by A. H. Thayer who .... has been able to see in them only an oblitera- ? tive? or concealing effecL Tracy defends the directlye theory most convincingly, both with argument and an array of fact, the latter de- rived from field observation of passerinc birds. The author under review brings out incontro- ,?ertibly the remarkable correlation existing between the possession of revealing (a .pre- ferred substitute for the word directlye) marks, the flocking habits, and use of location notes, in many birds which forage in the open. The significance of this correlation is self-evident. A fundamental point emphasized by Tracy is the usual association of motion with the opti- ?mllm display of contrasted markings. Perfect quiRts.on the part of a bird possessing such a pa?tern.might in truth result in obliteration against a checkered background; but quick movement, as when .the bird takes flight, brings the same pattern to the instant attention of the obser?,er. In other words the function o con- cealingmight be subserved by. the coloration of a. bir4? aZ rest,. when the same coloration would render the bird conspicuous in mo?ion. Tracy's attitude throughout is modest and Conservative. Although he clearly holds defi- nite views, he presents these always tenta- tively, giving the reader a fair chance to weigh the evidence pro and con. The paper in hand is well worth careful study by every observer of birds. Data. contributory to the solution of ?16?0blems of this nature are probably to be de- H?ve?ehiey from' observation of the living animal unde3 natural conditions. The devotee of field orni'thology will find here one way in which part of his horde of facts can be of use in a large field of philosophic inquiry.--J. G. BIRDS AND MAMMALS OF NORTHWESTERN COLORADO, BY A. H. FELGER. [The University of Colorado Studies, vol. vii, no. 2, January, 1910, pp. 132-14.6.] The report deals mainly with the species seen on an expedition into northwestern Col- orado, 'August I to September 4, 1909, but in- cludes as well "those reported on good author- ity from the region," the birds amounting altogether to 133 species. The annotations re- late principally ,to the manner and place of oc- currence of the species observed. Considered as the result of observations made during a single month the list is a long one; as a last of the birds cccurring?in that part of Colorado it is evidently incomplete, judging from state- ments in the introduction. It is hard to tell in which category the author wished it to fall. To the reviewer:the practice of including in such publications species which were .o? en- countered but which the author believes should occur there seenis objectionable. To take a particular instance in the present paper, under Olocoris alpeslris leucolaema the only state- merit made is that "not a singie bird of this common species was seen on the whole trip." If none were seen why is it considered a com- mon species, or why is it entered at all ? The paper will be of undoubted value to any one studying the distribution of birds in Col- orado, but such a student will be forced to ignore a number of the records.?H. S.S. THE TERRESTRIAL [ MAMMALS AND BIRDS [ OF NORTHEAST GREENLAND[ Biological Ob- servations [ by ] A. L. V. MANNIC/?E(=Danish Expedition to Northeast Greenland, 1906-1908, vol. v, no. 1; 1910; pp.l-200, figs. 1-20, pls. I-VII). For two years the author of the paper under notice was stationed on the northeast coast of Greenland at lat. 76 46'. The immediate vicinity of his permanent quarters fortunately proved to be surprisingly prolific of animal life, more so than any other parts of the adja- cent region which were visited at different seasons hy other members of the expedition. .Dr. Manniche devoted his'attention to a biolo- gical study of the neighborhood, and the pres- ent report on the eight species of mammals and thirty-eight of birds is proof of close observa- tion and discriminating judgmeut. Confiniug our attention to the portion of the work relating to birds, some 100 pages, we find exceedingly interesting accounts given of the breeding habits of such far northern visitors as the Knot, Sanderling and Ivory Gull. Eggs of the latter two were found. Although no eggs of the Knot were actually secured, close obser- vation' of the birds throughout the breeding season was possible. The account of the ptar- migan shows strikingly close agreement with the facts recorded of the Rock Ptarmigan of Alaska. The author shows a clear conception of the molt-processes, until not so very long ago obscurely understood. The courting and nidification of the Red Phalarope is most en- tertainiugiy narrated. Those interested in the problem of sexual coloration will find here some facts of significant bearing. The paper in hand is altogether of a biologi- cal and faunistic nature. Although brief des- criptive notes on the specimens secured are presented, there is no evidence of close syste- niatic enquiry. The nomenclature is scarcely recognizable from the standpoint of the A. O. U. Check-List, and no attention is given to subspecific distinctions. Thus the ptarmigan is "Lag'opus mutus", with no reference to L. rupesiris reinkardi. However, this cannot be emphasized as a fault, when the whole paper is avowedly concerned only with ecology and biography.--J. G.
