552 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



Darwin, C. 



1859. On the origin of species by means of natural selection, x + 502 pp. London: 

 J. Murray. 



Delacoue, J. 



1951. The Pheasants of the World. 347 pp. London: Country Life Ltd. 



Dickey, D. R., and A. J. van Rossem 



1938. The Birds of El Salvador. Field Mus. Nat. Hist. (Zool. Ser.), 23:1-635. 



DOIJZHANSICY, T. 



1937. Genetics and the Origin of Species, xviii + 446 pp. New York: Columbia Univ. 

 Press. 



Dresser, H. E. 



1871-1890. A history of the birds of Europe, including all species inhabiting the west- 

 ern palaearctic region. 9 volumes. London. 



Drost, R. 



1950. Study of bird migration 1938-1950. Proc. 10th Interuat. Ornithol. Congr., 216- 

 240. 



Elliot, D. G. 



1864-1865. A Monograph of the Tetraoninae: or, Family of the Grouse, xx + 52 pp., 



27 col. pis. New York. 

 1870-1872. A Monograph of the Phasianidae or Family of the Pheasants. 2 vols. New 



York. 

 1877-1882. A Monograph of the Bucerotidae, or Family of the Hornbills. xxxii + (2) 



+ 146 pp., 60 pis. (57 col.). London. 

 1895. North American Shore Birds, a History of the Snipes, Sandpipers, Plovers and 



Their Allies. . . . xvi + 17-268, 72 pis. New York. 



Engels, W. L. 



1940. Structural adaptations in thrashers (Mimidae: Genus Toxostoma) with com- 

 ments on interspecific relationships. Univ. Calif. Publ. Zool., 42:341-400. 



Earner, D. S. 



1950. The annual stimulus for migration. Condor, 52:104-122. 



FiNSCH, 0. 



1867-1868. Die Papagaien. 2 volumes. Leiden. 



PiNSCH, O., and G. Hartlaub 



1870. Die Vogel Ost-Afrikas. x + 897 pp. Leipzig. 



Fisher, H. I. 



1946. Adaptations and comparative anatomy of the locomotor apparatus of New 

 World vultures. Amer. Midi. Nat, 35:545-727. 



Friedmann, H. 



1929. The Cowbirds. xvii + 421 pp. Springfield, 111. and Baltimore, Md. : C. C. Thomas. 

 1948. The Parasitic Cuckoos of Africa. Wash. Acad. Sci. Monogr. No. 1. 204 pp. 



FiJRllRINGER, M. 



1888. Untersuchungen zur Morphologie und Systematik der Vogel, zugleich ein 

 Beitrag zur Anatomie der Stiitz-und Bewegungsorgane. 2 vols, xlix + 1751 

 pp. Amsterdam: van Holkema. 



Gadow, H. F. 



1891. Vogel. In Bronn's Klassen und Ordnungen des Thier-Reichs, Vol. 6. 1008 pp. 

 Leipzig: C. F. Winter. 



