Many natural enemies prey upon the racer, but in the present study the majority of records pertained to the red-tailed hawk. The broad-winged hawk, marsh hawk, red-shouldered hawk, sparrow hawk, and barn owl also are among the raptors that feed on this kind of snake. Among mammals the striped skunk is the only species definitely recorded to prey on the racer, feeding on the eggs as well as upon the young and adults. The common king snake, prairie king snake, timber rattlesnake, copperhead, and even the slender glass lizard have been recorded to prey on the blue racer, but probably all are of minor importance as natural enemies. Shrews (_Blarina_, _Cryptotis_) and mice (_Peromyscus_, _Reithrodontomys_) have sometimes killed and eaten racers confined in traps, and under natural conditions they possibly prey upon snakes that are immobilized when torpid from cold, in their hibernacula and temporary shelters. Chiggers are the most common ectoparasites of the racers. Four species of the chigger genus _Trombicula_ have been recorded on racers from the Reservation. The racer is an important host of the common pest chigger, _Trombicula alfreddugèsi_, which often attacks humans. Most adult racers on the Reservation and nearby areas carry the fluke, _Neorenifer lateriporus_. In spring these flukes are conspicuous in the mouths of the racers, but in late summer they are not in evidence. Literature Cited Allen, M. J. 1932. A survey of the amphibians and reptiles of Harrison County, Mississippi. Amer. Mus. Novit., 542:11-12. Anderson, P. 1942. Amphibians and reptiles of Jackson County, Missouri. Bull. Chicago Acad. Sci., 6:203-220. Atkinson, D. A. 1951. The reptiles of Allegheny County, Pa. Ann. Carnegie Mus., 1:145-157. Auffenberg, W. 1949. The racer, _Coluber constrictor stejnegerianus_ in Texas. Herpetologica, 5:53-58. 1955. A reconsideration of the racer, Coluber constrictor, in eastern United States. Tulane Studies in Zool., 2(6):89-155. Barbour, R. W. 1950. The reptiles of Big Black Mountain, Harlan County, Kentucky. Copeia, 1950:100-107. Baxter, G. T. 1947. The amphibians and reptiles of Wyoming. Wyoming Wild Life, August and October 1947:1-8. Blair, W. F. 1960. The rusty lizard. Univ. Texas Press, Austin, xvi + 185 pp. Blanchard, F. N. and Blanchard, F. C. 1942. Mating of the garter snake, _Thamnophis sirtalis sirtalis_ (Linnaeus). Papers Michigan Acad. Sci. Arts and Letters, 27:215-234. Blanchard, F. N. and Finster, E. B. 1933. A method of marking living snakes for future recognition with a discussion of some problems and results. Ecology, 14:334-349. Bogert, C. M. and Cowles, R. B. 1947. Moisture loss in relation to habitat selection in some Floridian reptiles. Results of the Archbold Expeditions, No. 58; Amer. Mus. Novit., 1358:1-34. Bonn, E. W. and McCarley, W. H.