258 APPLIED BACTERIOLOGY 



at an obtuse angle against the handle) the three droplets 

 thus deposited were carefully and gently spread over the 

 agar surface, the dishes were duly covered over, and were 

 incubated at 37° C. After two or three or more days, 

 all the colonies able to grow on these media had commonly 

 made their appearance, and could be easily studied. The 

 organisms obtained by Klein from variolous crusts by this 

 method were the following : A number of common sapro- 

 phytes, organisms of the pyogenic class, a non-pathogenic 

 bacillus known as the Leptothrix epidennidis, which organism 

 was first isolated from epidermic scales by Bizzozero, an 

 organism which Klein called the Bacillus Xerosis variola. 

 This organism closely resembled the so-called pseudo- 

 diphtheria bacilli ; but the most important organism 

 isolated was the following : 



Bacillus alhus variolce. — This organism gives a pure 

 white growth on agar. The colonies on a plate culture 

 are moist-looking, grow fairly rapidly, and are slightly 

 raised. In stained specimens the organisms are seen as 

 small delicate rods with rounded ends, measuring O'8-l /i, 

 the thickness of the rods being about one-thi|d or fourth 

 the length. Subcutaneous injection of agar cultures of this 

 bacillus into guinea-pigs and rabbits produced no result, 

 but cutaneous insertion into calves gave very interesting 

 results, in two or three cases appearances of typical variola 

 being obtained, which in one case at least was obtained 

 after two removes. It is most probable that after further 

 work this will be found to be the true specific organism ; 

 but the matter is at present sub judice, and the further 

 developments of Dr. Klein's researches will be of the 

 greatest interest. 



Jennerian Vaccination. — As is well known, vaccinia can 

 be inoculated into human beings by means of the lymph 

 taken from the vesicles, the operation being known as 



