1887. Ueber die Bestimmung des Plankton’s oder des in Meere treibenden Materials an Pflanzen und Thieren; nebst Anhang. Fünfter Ber. der Komm. zur wissensch. Untersuch. d. deutschen Meere in Kiel für die Jahre 1882 bis 1886, pp. 1-107, III-XVIII, Berlin. This appears to be the original account of quantitative studies as applied to plants and animals of an association. These methods have been extended to the sea bottom by Petersen, to fresh water by many students, to land animals mainly by Dahl, and in recent years to plants by Clements and others. HERRICK, C. L. 1905. Home Life of Wild Birds. Revised Edition, pp. 255. New York. Very valuable for suggestions on the study of live birds and how to photograph them. HOPKINS, A. D. 1893. Note and Record Keeping for the Economic Entomologist. U. S. Dept. Agr., Div. Ent., Insect Life, Vol. VI, pp. 103-108. JOB, H. K. 1910. How to Study Birds. A Practical Guide for Amateur Bird-Lovers and Camera-Hunters, pp. 272. New York. Outing Publishing Co. Intended primarily for beginners in bird study, but contains valuable practical advice on methods of studying and photographing live birds which will aid the ecologist. Consult also Kearton (1907), Chapman (1900), and Herrick (1905). KEARTON, R. 1907. Wild Life at Home: How to Study and Photograph It. New and Revised Edition, pp. 204. London. KEPHART, H. 1912. The Book of Camping and Woodcraft. pp. 331. Fifth Edition. Outing Publishing Co. This is the best all-round book on the technique of camping and living in the wilderness which I have seen. It includes direction for selecting outfits, making camps, cookery, pests in the woods, blazes and survey lines, rations, emergency foods, getting lost, accidents, etc. KNAUTHE, K. 1907. Das Süsswasser, chemische, biologische, und bakteriologische Untersuchungsmethoden unter besonderer Berücksichtigung der Biologie und der fischereiwirtschaftlichen Praxis. pp. 663. Neudamm. A very important work on the technique of fresh water biology. LEE, A. B. 1900. The Microscopist’s Vade Mecum. A Handbook on the Methods of Microscopic Anatomy. Fifth Edition, pp. 532. Phila. Very useful for methods of preserving delicate animals, and those in which the detailed structure of the animal must be studied. LIVINGSTON, B. E. 1906. The Relation of Desert Plants to Soil Moisture and to Evaporation. Carnegie Inst. Pub. No. 50. pp. 78. Methods of determination of moisture content of the soil and the air. MCATEE, W. L. 1907. Census of Four Square Feet. Science, N. S., Vol. XXVI, pp. 447-449. A quantitative study of the species of invertebrates and seeds found on the forest floor and on a meadow. 1912. Methods of Estimating the Contents of Bird Stomachs. The Auk, Vol. XXIX, pp. 449-464. 1912. The Experimental Method of Testing the Efficiency of Warning and Cryptic Coloration in Protecting Animals from their Enemies. Proc. Acad. Nat. Sci. Phila., 1912, pp. 281-364.