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 264 THR CONDOR Vol. XVI Marsh at the head of Cayuga Lake, near Cornell University, Ithaca, New York, and cover a period of several years. Mr. Allen begins the paper with a description of the topographic features of the marsh, its cli- matic conditions and zonal position. The floras and vertebrate faunas of the several associations are described in detail. The following seven associations are distin- guished: open-water, shore-line, cat-tail, sedge, grass, alder-willow, and maple-elm. Some attention is devoted to the succession of associations and the factors which con- trol such succession. A graphic representa- tion following a method commonly used by paleontologists to portray the persistence of faunas shows the associational distribution of the commoner birds and aids in making clear, this,-to some, rather intangible segre- gation of species. After thus describing its environment, the life history and ecology of the Red-wing are taken up, the following topics being consid- ered: Spring migration, mating ahd song, nesting, the young, fall migration, enemies, molt and plumage, food and food supply, correlation between changes in food and changes in structure of stomach, and corre- lation of changes occurring in the reproluct- ive organs. 'Seven categories of individuals during the spring migration are distinguished. These, with their typical dates of arrival at Ren- wick Marsh, are as follows: "Vagrants",. Feb. 25-Mar. 4; Migrant adult males, Mar. 13-Apr. 21; Resident adult males, Mar. 25- Apr. 10; Migrant adult females and imma- ture males, Mar. 29-Apr. 24; Resident adult females, Apr. 10-May 1; Resident immature males, May 6-June 1; Resident immature females, May 10-June 11. Mr. Allen solves the "mysterious disap- pearance" of the Red-wings for a period after the breeding season by finding that the period in question is that of active molt and that the birds then restrict themselves to the thick growths of rules where they are secure from their enemies. A correla- tion between the nature of the food and the structure of the stomach was discovered. The musculature of that organ becomes heavier when the birds are feeding upon seeds than when they are subsisting upon insects. Perhaps the most novel thing in the whole paper is Plate XXI which shows the rela- tive development of the testes and ovaries in resident and migrant birds. A gradual increase in size is demonstrated in both res- idents and migrants; but corresponding stages appear a month later in the latter category, so that of two birds collected on any one day in March or April in the same locality, the organs of the resident will be much more fully developed than in the mi- grant. Altogether the paper is an excellent ex- ample of painstaking, intensive work, re- plete with observations and relatively free from speculation. Mr. Allen has furnished a standard that future students in the same field may follow to advantage. It will also serve well as a source of information for teachers of ornithology.--TRAcY I. STOER. THE BIRDS [ OF I EL PASO COUNTY [ COL' OR,DO [ By CHARL.S E. H. AKEN EDWARD 1:. WARREN I Director of the Muse- um, Colorado College I Parts I and II.---Col- orado College Publication; general series, nos. 74, 75, 76; science series vol. x, no. 13, I, pp. 4q-455-496, 2 maps, 15 half-tone figs. on 8 pls.; II, pp. 2-497-603-[-9 (unpaged index), pls. ix-xxIv which contain half-tone figs. 16- 45. Dates on covers: I, May, 1914; II, June- September, 1914. Our copy, both parts, re- ceived July 20, 1914. We have here the most comprehensive county bird list that has come to our' atten- tion for a long time. It is far more than a faunal list, nearly every species being ac- corded more or less biographical treatment, besides full distributional consideration, and occasional critical or systematic notice. The association of these two authors is a happy one. Mr. Aiken, truly a pioneer, came to Colorado Springs in 1871, and his large collections and notes covering a long period of years contribute to the complete- ness of the report. The junior author, Mr. Warren, has been doing bird work in E1 Paso County steadily for the past dozen years. To him has evidently fallen most of the work of compiling the text and seeing to the details of publication. The paper includes, besides the main annotated list, .paragraphs or chapters on topography, life zones, climate, history, bibliography, and analysis of the avifauna Two maps acquaint the reader with the lay of the land; while forty-five half-tone cuts of birds, nests, and eggs add decidedly to the attractiveness of the paper. We have found in this contribution sev- eral points of particular interest, to only two of which, however, can space here be spared for reference. Exception is taken by Aiken and Warren to the ruling of the A. O. U. Committee regarding the occur- rence in Colorado of all three forms of A- tcalais psatia, namely, lsatei, nae, and neican. Oberholser's view, cen-