1881. A System of Logic, Ratiocinative and Inductive: Being a Connected View of the Principles of Evidence and the Methods of Scientific Investigation. Eighth Edition, pp. 659. New York. PEARSON, K. 1900. The Grammar of Science. Second Edition, pp. 548. London. JEVONS, S. 1879. Principles of Science. Third Edition, pp. 786. London. Certain chapters are of special interest. CRAMER, F. 1896. The Method of Darwin. A Study in Scientific Method, pp. 232. Chicago. MACDOUGAL, ROBT. 1905. On the Discrimination of Critical and Creative Attitudes. Jour. Philos. Psy. and Sci. Methods, Vol. II, pp. 287-293. LEBON, G. 1898. The Life History of Scientific Ideas. Pop. Sci. Mo., Vol. LII, pp. 251-254. _2. Directions for Collecting and Preserving Specimens, Photographing, Surveying, and Other Phases of Technique_ There is such an abundance of literature on the technique of collecting and preserving specimens, and so much of it can easily be secured by any earnest student, that space will not be taken to discuss these subjects in detail. Reference will simply be made to the main convenient sources of information. It should perhaps be mentioned that very few of these papers have been especially prepared from the standpoint of the animal ecologist. The student must select and devise his methods from all available sources. I have included in this list a few references on the subject of camping, photography, and the use of instruments needed in the determination of the physical features of the environment. A few miscellaneous papers which are suggestive on methods of technique are also added. MANY AUTHORS. 1891-1899. Bulletin 39, U. S. National Museum. Parts _A_ to _O_. Contain directions for collecting and preserving a great variety of animals, including marine animals, mollusks, insects, spiders, myriapods, reptiles, amphibians, birds, birds’ eggs and nests, mammals, etc. ANONYMOUS. 1896. Manual for Army Cooks, pp. 306. Washington. The Manual used by the cooks in the U. S. Army. It includes chapters on camp cooking, a subject of much importance in certain ecological surveys. 1905. Terms used in Forestry and Logging. Bull. 61, Bureau of Forestry, U. S. Dept. Agr. pp. 53. Useful in the descriptions of forest conditions. 1904. Instructions to Field Parties and Descriptions of Soil Types. Bureau of Soils, U. S. Dept. Agr. pp. 198. Useful in the description of soils in the study of subterranean animals. BANKS, N. 1907. A “Census of Four Square Feet.” Science, N. S., Vol. XXVI, p. 637. A criticism of McAtee (1907). 1909. Directions for Collecting and Preserving Insects. Bull. 67, U. S. Nat. Mus. pp. 135. An excellent manual. Should be in the hands of every student of insects. BRETSCHER, K. 1902. Beobachtung über die Oligochaeten der Schweiz, VI. Folge. Rev. Suisse de Zoöl., Ann. Soc. Zoöl. Suisse et du Mus. d’His. Nat. de Geneve, Tome 10, pp. (1-29).