246 SUMMARY OF CURRENT RESEARCHES RELATING TO 



into animals, and observation of the lethal dose. He finds that the 

 pneumococcus grows as well in the presence of immune sera, active or 

 inactivated, as in normal serum, the organisms are agglutinated, so that 

 the broth remains almost clear. Grown in broth containing immune 

 serum, the pneumococcus rapidly loses its virulence. This loss does not 

 appear to be proportional to the immunising power of the serum. 

 Subcultures from a pneumococcus, thus deprived of virulence, act also 

 avirulent. The immune bodies have no catalytic action, but appear to 

 cause paralysis of those vital processes of the organism which render it 

 virulent. Immune bodies from sera of such different animals as the 

 rabbit and the ass, appear in relation to the pneumococcus to be indis- 

 tinguishable. The streptococcus does not lose its virulence in the 

 presence of immune sera, but otherwise its behaviour is similar to that 

 of the pneumococcus. 



The active principles of anti-pneumococcic and anti-streptococcic sera 

 lose their individuality after contact with these organisms. The 

 bacteriotropic function of these sera consists probably in a lesser degree 

 of an antitoxic action and in a greater degree in an action upon the 

 bacteria, which inhibits the formation of those toxic substances upon 

 which the pathogenicity depends. The organism, thus reduced to the 

 state of an ordinary saprophyte, is taken up by a phagocyte and 

 destroyed. 



Mouse Epizootic due to a Coliform Bacillus.* — G. Sangiorgi 

 describes a spontaneous epizootic among the white mice at the Hygienic 

 Institute of Turin, which killed 20 p.c. of these animals. The principal 

 symptoms were subnormal temperature, distressed breathing, great weak- 

 ness of the hind legs, profuse diarrhoea, and emaciation. The autopsy 

 revealed patches of necrosis on the surface of the liver, enlargement of 

 the spleen, and marked pallor of the kidneys. From spleen and heart- 

 blood an organism was obtained, which corresponded culturally and 

 morphologically with Bacillus coli communis in every point but one, viz. 

 that it did not clot milk before 7 or 8 days at 37°, and no clotting 

 occurred at room-temperature. Rats and mice fed with cultures died, 

 the latter in 5 to 6 days, the former in 8 to 11 days. Cats suffered 

 from profuse diarrhoea as long as the administration continued, but did 

 not usually succumb. Intraperitoneal inoculations killed mice, rats, 

 rabbits, and guinea-pigs very quickly. 



Characters of Cholera and Cholera-like Organisms.f — This study 

 has been carried out by A. J. McLaughlin and E. R. Whitmore with a 

 view to settling some points concerning certain vibrios encountered in the 

 Philippine Islands. The first point was whether any cholera-like vibrios 

 might agglutinate in a low dilution of a specific anti-cholera serum and 

 thus lead to error. The second point was whether cholera vibrios lose 

 their morphological character or agglutinability under any circumstances, 

 but especially in mixed cultures sent on a long journey for diagnosis. 

 Every vibrio examined by the authors which agglutinated in a 1 : 200 



* Centralbl. Bakt., lte Abt. Orig., lvii. (1910) pp. 57-9. 

 t Philippine Journ. Sc : .,v. B., pp. 403-32. 



