314 IMPORTANT VARIETIES OF FISSION-FUNGI. 



large quantities of virulent spores (Koch), but has proved 

 very successful practically in anthrax regions (Pasteur). 

 Hankin has tried to produce an immunity in animals 

 with the metabolic products of anthrax without positive 

 results; the serum from sheep in which a very high active 

 immunity has been produced possesses immunizing action 

 only for sheep and not for rabbits (Sobernheim). The 

 bactericidal power of the serum in vitro is not increased 

 over the serum from normal animals. The serum does 

 not cause agglutination. Sobernheim considers the in- 

 jection of a mixture of immune sheep serum (16 c.c.) 

 and attenuated bacilli {^ loopful) to be the most certain 

 method of conferring a more lasting vaccination protec- 

 tion (Sobernheim, Z. H. xxv, 301; and xxxi, 89). 

 Emmerich and Low have observed very noticeable cura- 

 tive and immunizing results in rabbits from pyocyanase 

 (p. 110). 



Special Methods for Demonstration and Differen- 

 tial Diagnosis. — If the question, as is usual, is one of 

 diagnosis in an infected man or animal, very often a good 

 preparation of smeared blood stained by Gram's method 

 gives valuable results. For the differential diagnosis ordi- 

 nary agar plates are especially to be prepared, which, after 

 seventeen to twenty-four hours in the incubator at 37°, 

 present spores within threads. Also observations as to 

 motility are useful, as also are sugar-agar shake cultures. 



The Differential Diagnosk between the Varieties which most 

 Come in Question, may be Represented as Folloios : 



