ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 229 



Agglutinins and other anti-bodies were demonstrated, and complement 

 fixation experiments were positive. 



Sero-Diagnosis of Plague by Means of Ascoli's Precipitation 

 Method.*^H. Berlin has carried out a series of experiments with anti- 

 gens prepared from plague-infested organs, the orgau-pulp being 

 mixed with 5 to 10 times its volume of normal salt solution, heated in 

 the water-bath, and then filtered till quite clear. The agglutinating 

 serum was employed in a dilution of 1 in 200. The precipitation tubes 

 were incubated at 87' C, and examined for precipitation zoning after 

 5 and 30 minutes respectively. When the reaction was positive, a 

 cloudy ring was formed at the junction of the antigen and the serum 

 in the tubes. The antigen was present in the organs of animals dead 

 with eitlier natural or artificial infection, and the reaction occurred 

 with both fresh and putrid organs ; in the latter case, however, with 

 less frequency. The intensity of the cloud-ring was found to be 

 dependent on the amount of plague bacilli contained in the organ. 

 The action is not specific : positive results were sometimes obtained 

 with the controls containing extracts of the organs of normal healthy 

 animals (rats and guinea-pigs). For this reason Ascoli's method cannot 

 take the place of the ordinary means of bacteriological diagnosis of 

 plague, and can only be regarded as a method of additional investi- 

 gation. 



Pus-generating Diphtheroid Bacillus.t — A. D. Pavlovsky has 

 isolated the BaciUus ijyogenes alhus diphtheroides (first described by him 

 in 1909) from twelve cases of suppurating gun-shot wounds met with on 

 the Russian Front. In six cases the bacillus was in pure culture ; in the 

 remaining cases, mixed with staphylococci. The organism is usually 

 located outside the pus-cells, is Gram-positive, and resembles a recently 

 cultivated diphtheria bacillus. It grows on agar and on LoeflBer's 

 serum in from twenty to twenty-four hours, and does not liquefy 

 gelatin. (Tuinea-pigs inoculated in the abdominal cavity with 1 c.cm. 

 of broth culture die in about two days, positive cultures being recovered 

 from the liver and spleen. Clinically, suppuration with formation of 

 greyish or whitish-grey pus, fever (102° F.), and occurrence of fistulse 

 are present, but the infection is localized and the prognosis good. 

 Pavlovsky considers that this bacillus should be added to the group of 

 primary suppurative organisms. 



* Centralbl. f. Bakt., IteAbt. Orig.,lxxv. (1915) pp. 467-85. 

 t Russkiy Vrach (Petrograd) xiv. (1915) pp. 721-3. 



April 19th, 1916 r 



