ROBERT S. BREED 381 



mastitis var. sporadicae and S. mastitis var, contagiosae Guillebeau have priority. Such 

 confusion in names can only be settled by international agreement. If the binomial 

 is attributed to Guillebeau, it should be spelled S. mastitis. 



Brown, Frost, and Shaw,' following up the work of Smith and Brown,' have recog- 

 nized the streptococcus of septic sore throat as an organism that may become localized 

 in the udder. They have characterized this organism by its capsule formation, failure 

 to hydrolyze sodium hippurate, failure to ferment mannite, and fermentation of sali- 

 cin, and have accepted the name S. epidemicns Davis as the name of the species. In 

 their work, cows were found whose udders were infected with this capsulated strepto- 

 coccus, but no direct evidence was secured that they had caused cases of human septic 

 sore throat. Frost, Gumm, and Thomas^ have later recognized as many as eight 

 species of streptococci found in the udder. 



INFECTION OF THE UDDER WITH "BACTERIUM ABORTUS" 



The success of Evans^ in demonstrating the presence of Bang's bacillus of con- 

 tagious abortion in milk as drawn from the cow's udder, and her recognition of the 

 resemblance between this organism and the causal organism of Malta fever {Micro- 

 coccus melitensis Bruce) isolated from the goat's udder, has directed the attention of 

 several investigators to the possibility that Brucella abortus may cause human disease. 

 The resemblance between these two organisms is so close that no really satisfactory 

 diagnostic methods have yet come into current use, although it is generally believed 

 that the two organisms represent separate species. Carpenter, s Huddleson,^ and 

 others have recently found cases of undulant fever in man apparently caused by the 

 use of cow's milk containing Bacterium abortus. 



LEUKOCYTES AND OTHER BODY CELLS IN MILK 



The presence of mastitis streptococci in the glandular tissue of the udder has been 

 shown by Baker and Breed-' to cause the entrance of only partially elaborated blood 

 serum into the alveoU without the usual change in H-ion concentration from that of 

 normal blood (pH 7.0) to that of normal milk (pH 6.5-6.6). In spite of the fact that 

 mastitis streptococci are lactose-fermenters, and must transform this sugar into acid 

 in the individual alveoli, the H-ion concentration of the milk, as drawn from infected 

 quarters, approaches that of normal blood serum. Accompanying this entrance of a 

 serous exudate into the milk, there is an increase in the migration of leukocytes 

 through the walls of the alveoli so that mastitis milk usually contains excessive num- 

 bers (millions per cubic centimeter) of these blood cells. 



It is probable that infections with other pathogenic bacteria such as Brucella 

 abortus, or even purely physiological disturbances, may cause the same phenomenon. 



• Brown, J. H., Frost, W. D., and Shaw, M.: /. Infect. Dis., 38, 381. 1926. 

 ' Smith, T., and Brown, J. H.: /. Med. Research, 31, 455. 1915. 

 3 Frost, W. D., Gumm, M., and Thomas, R. C: J. Bad., 13, 61. 1927. 



■» Evans, A. C: /. Infect. Dis., 23, 354. 1918; Hyg. Lab., U.S. Pub. Health Ser., Bull. 143. 1925. 

 s Moore, V. A., and Carpenter, C. M.: Cornell Vet., 16, 147. 1926; Carpenter, C. M.: /. Am. 

 Vet. M. A., 70, 459. 1927. 



''Huddleson, I. F.: J.A.M.A., 86, 943. 1926. 



7 Baker, J. C, and Breed, R. S.: New York Agric. Ex per. Sta. {Geneva) Tech. Bull. So. 1920. 



