SURFACE, H. A. 1906. The Serpents of Pennsylvania. Penn. Dept. Agr., Monthly Bull., Vol. IV, pp. 113-208. Observations on food of serpents. 1908. First Report on the Lizards of Pennsylvania. Penn. Dept. Agr., Zoöl. Bull., Vol. V, pp. 233-264. Food of lizards. 1908. First Report on the Economy of Pennsylvania Turtles. Penn. Dept. Agr., Zoöl. Bull., Vol. VI, pp. 107-195. Many observations on food. WARD, H. B. 1910. Internal Parasites of the Sebago Salmon. U. S. Bur. Fisheries, Bull., Vol. XXVIII, pp. 1151-1194. “The parasitic fauna of any animal is primarily a function of its habitat.” p. 1191. 1912. The Influence of Hibernation and Migration on Animal Parasites. Proc. Seventh Inter. Zoöl. Cong., Boston, 1907, pp. 673-684. WASMANN, E. 1894. Kritisches Verzeichniss der Myrmekophilen und Termitophilen Arthropoden. pp. 231. Berlin. A list of Arthropods found living with ants and termites. WEBSTER, F. M. 1903. Notes upon the Food of Predaceous Beetles. Bull. Ill. State Lab. Nat. Hist., Second Edition, Vol. I, pp. 162-166. WEED, C. M., and DEARBORN, N. 1903. Birds in their Relations to Man. pp. 380. Phila. Extensive bibliography on the food of birds. WHEELER, W. M. 1911. Insect Parasitism and its Peculiarities. Pop. Sci. Mo., Vol. LXXIX, pp. 431-449. 1910. The Effects of Parasitic and Other Kinds of Castration in Insects. Jour. Exp. Zoöl., Vol. VIII, pp. 377-438. ZACHARIAS, O., and others. 1891. Die Tier- und Pflanzenwelt des Süsswassers. Bd. I, pp. 380; Bd. II, pp. 369. Leipzig. Contains several valuable and suggestive papers on the general biological relations of fresh-water plants and animals. _2. The Dynamic Relations of Aggregations and Associations, with Special Reference to Animal Associations_ “A group or association of animals or plants is like a single organism in the fact that it brings to bear upon the outer world only the surplus of forces remaining after all conflicts interior to itself have been adjusted. Whatever expenditure of energy is necessary to maintain the existing internal balance amounts to so much power locked up, and rendered unavailable for external use. In many groups this latent energy is so considerable and is liable to such fluctuations, that a knowledge of its amounts and kinds, and of the laws governing its distribution, is extremely important to one interested in measuring or foreseeing the sum and character of the outward-tending activities of the class.” --S. A. FORBES (1883). MÖBIUS, K. 1883. The Oyster and Oyster-Culture. U. S. Comm. of Fish and Fisheries, Report of Comm. for 1880, Part VIII, pp. 683-751.