NATURAL AND ACQUIRKI) IMMUNITY 127 



Webster, L. T., and Burn, C. G. : Biology of Bacterium Lepisepticum. III. 

 Physical, Cultural, and Growth Characteristics of Diffuse and Mucoid 

 Types, and Their Variants, J. Exper. Med. 44: 343, 1926. 



Webster, L. T., and Burn, C. G.: Biology of Bacterium Lepisepticum. IV. 

 Virulence of Diffuse and Mucoid Types, and Their Variants, J. Exper. 

 Med. 44: 359, 1926. 



Webster, L, T., and Hodes, H. L.: Role of Inborn Eesistance Factors in 

 Mouse Populations Infected With Bacillus Enteritidis, J. Exper. 

 Med. 70: 193, 1939. 



Wells, A. Q.: Tuberculosis in Wild Voles, Lancet 1: 1221, 1937. 



Wells, A. Q., and Brooke, W. S.: The Effect of Vaccination of Guinea 

 Pigs With the Vole Acid-Fast Bacillus on Subsequent Tuberculosis 

 Infection, Brit. J. Exper. Path. 21: 104, 1940. See also Editorial in 

 J. A. M. A. 116: 509, 1941. 



Wells, J. R. : The Origin of the Immunity to Diphtheria in Central and 

 Polar Eskimos. I. A Study of the Throat Flora, Am. J. Hyg. 18: 629, 

 1933. II. Epidemiological and Serological Studies, Ibid., p. 656. 



Zinsser, H. : Immunology of Infections by Filtrable Agents and Epidemiology 

 and Immunity in Rickettsial Diseases. Virus and Rickettsial Diseases, 

 Harvard Univ. Press, 1940, pp. 89 and 872. 



Zinsser, H., and Bayne- Jones, S.: Textbook of Bacteriology, ed. 8, New 

 York, 1939, D.'Appleton-Century Co., p. 791. 



Zinsser, H., Enders, J. F., and Fothergill, L. D.: The Prophylaxis of Pneu- 

 monia by Vaccines and Various Immunologic Constituents of Pneumo- 

 coccal Cells, Immunity, ed. 5, Eesistance to Infectious Diseases, New- 

 York, 1939, The Macmillan Co., p. 688. 



Supplementary References 



Almon, L., and Stovall, W. D.: A Study of ''Vi" Antigen of Felix and 



Pitt, J. Immunol. 31: 269, 1936. 

 Campbell, D. H.: The Effect of Sex Hormones on the Normal Eesistance of 



Rats to Cysticercus Crassicollis, Science 89: 415, 1939. 



