ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 487 



of persons recovering from the diseases caused by these latter organisms 

 nor by the sera of hyper-immunized animals <B. typhosus, B. coli, 

 B. paratyphosus A and B). The organism cannot be identified with 

 B. paratyvhosus G Uhlenhutk, as the latter (which is apparently identical 

 with B. suipestifer) is apparently not pathogenic to man. 



Mutations of Plague Bacilli.* — J. G. Markl, working with agar 

 plates wkick kad been inoculated from buboes, blood, and spleen 

 from cases of botk kuman and rat plague, was able to identify three 

 separate and distinct kinds of pest colonies which he distinguished as 

 A, B, and C colonies respectively. The Type A colonies are described 

 as delicate, translucent growths with strongly indented edges ; they are 

 non-slimy and are adherent to the culture media. The Type B colonies 

 are large colonies with slimy yellowish centres and with bluish indented 

 transparent edges. The Type C colonies are without border and are 

 small, roundish, and opaque. 



The A strain represents the youngest form, as it is in evidence on all 

 cultures during the first 24 hours ; the other types originate from the 

 A colonies and may be regarded as conservative forms called into being 

 through the needs of race preservation. Of tke tkree races, tke A race 

 is tke most virulent. Tke A race differs microscopically from tke B and 

 C race, being longer, ovoid, and uniformly staining, wkile tke otker races 

 appear as cocco-bacilli, wkick, kowever, on introduction into tke animal 

 body, develop into tke A strain. Tke different strains cannot be 

 regarded as true mutants, as tkey do not preserve kereditary constancy. 



Flies in Relation to the Transmission of Leprosy. f— J. A. Honeij 

 and R. R. Parker kave demonstrated tke appearance of acid-fast bacilli 

 in tke excreta of flies, wkick kave fed on tke lesions of persons suffering 

 from infection witk tke Bacillus leprae. Various species of dipterous 

 flies were tried in tke experiments, but positive results were only 

 obtained witk tke kouse-fly (Musca domestica) and tke stable-fly 

 (Stomoxys calcitrans). Witk tke latter species 80 p.c. gave acid-fast 

 bacilli in tke excreta, but in only one case were suck bacilli found in 

 " vomit spots." Flies caught at a distance of 250 yards from the 

 patients' dwellings, did not harbour acid-fast bacilli in their alimentary 

 tract. 



Pigment-forming Vibrio. J — Jennie G. Drennan describes the ap- 

 pearance of a chromogenic vibrio wkick was isolated from tke kuman 

 alimentary canal in a case of intestinal disturbance. 



Tke organism is a large motile vibrio producing a large wkite moist 

 colony on alkaline agar, turning slowly to a dark rick brown coloration. 

 Tke vibrio is an aerobe and facultative anaerobe, and liquefies gelatin 

 slowly. It produces acid in dextrose and sacckrose peptone, but not in 

 lactose, is slowly kemolytic, and does not form indol. It possesses but 

 one flagellum, and is Gram-negative. 



* Centralbl. Bakt., !> Abt. Orig., lxxiv. (1914) pp. 529-40. 

 t Journ. Med. Research, xxx. (1914) pp. 127-30. 

 % Journ. Infect. Diseases, xiv. (1914) pp. 251-4. 



