712 SUMMARY OF CURRENT RESEARCHES RELATING TO 



are white and of various shapes. In bouillon a dense white deposit is 

 thrown down. It grows well also on potato or biood-seruin, and in milk. 

 The casein in milk cultures is first coagulated and then dissolved. It 

 does not produce gas or form indol. The germination of spores was ob- 

 served from samples taken from an old agar culture and sown in gelatin. 

 As the spore enlarged it became less and less refractile. " The rod 

 emerged from one of the poles and grew outwards until the protruded 

 end was as long as the spore-case. By this time the distinction between 

 rod and spore bad practically disappeared. A protrusion then appeared 

 at the other end of the spore-case, and growth proceeded in two direc- 

 tions. The spore-case was then thrown off. and this was followed by 

 division of the lengthened rod into two parts. The daughter bacillus 

 from the end last to emerge, slowly bent round until it was at an angle 

 of 45° with the other rod, when it suddenly slipped along the side of 

 the latter. Germination occurred in 3^ hours at laboratory temperature 

 (20°) ; an hour later there were two cells, and in another four bacilli." 

 The affinities of the microbe are then discussed, and the differences 

 between B. jpiacicidus hipolaris and other organisms alluded to. 



Bacillus Pathogenic to Carassius auratus.* — Dr. J. Ceresole de- 

 scribes a bacterium which caused an epizootic among specimens of 

 Carassius auratus kept in an aquarium. The principal lesion was an 

 ulcer at the back of the head. Bacterioscopic observations showed the 

 presence of a bacillus 2-2*5 /x long by 0*8-0 '9 /x broad. It is motile, 

 stains well, and is easily cultivated. It is a potential anaerobe ; its 

 optimum temperature is 18° C. The cultures exhale the decomposition 

 odour. At first the growth is white or yellowish, but later on may be- 

 come red. Gelatin is liquefied. The virulence of the organism rapidly 

 decreases in artificial cultures. Indol is formed in beef-broth cultures. 

 The bacillus is very pathogenic to rabbits as well as to Carassius auratus. 

 It is found in large numbers in the blood of these fish dead of the 

 disease. Other fish inoculated with pure cultures were unaffected. From 

 the appearances found the new microbe is designated the bacillus of 

 ulcerative septicaemia of Carassius auratus. 



Varieties of Pseudodiphtheria Bacilli, j — Dr. D. Gromakowsky 

 states that there are three kinds of pseudodiphtheria bacilli, which are 

 distinguished by their cultural characters and by their growth in 

 bouillon : — (1) is a relatively thick rodlet of variable length, which 

 does not render bouillon turbid. It resembles Loeffler's bacillus in 

 staining by Neisser's method, and in the acid reaction which it developes 

 in bouillon. Its distinguishing characters are its large size and its 

 cultural appearances. (2) is a rodlet, of medium thickness and length, 

 which after 24 hours at 36° C. renders bouillon markedly turbid and 

 causes a copious deposit. Morphologically and culturally it closely 

 resembles Loeffler's bacillus. Its distinguishing feature is the absence 

 of acid reaction in bouillon and a negative Neisser staining. (3) is a 

 short, thin rodlet which causes only flight cloudiness in the medium 

 and a scanty deposit. It has some resemblance in appearance to 

 Loeffler's bacillus. 



* Centralbl. Bakt. u. Par., l te Abt., xxviii. (1900) pp. 305-9. 

 t Tom. cit., pp. 130-43 (3 figs.). 



