448 A MANUAL OF BACTERIOLOGY 



gelatin plates it forms small whitish colonies, visible within twenty 

 hours, which grow more rapidly than the cholera vibrio, and in 

 two or three days produce marked areas of liquefaction. In a 

 stab-culture in gelatin a whitish granular growth occurs along the 

 line of puncture with liquefaction, much like that of the Koch 

 vibrio, but the rate of growth and the liquefaction are more 

 rapid (Plate XVIII. c). Grown in eggs by Hueppe's method 

 typical appearances are produced. After ten days the white becomes 

 transformed into a yellowish limpid liquid, while the yolk, though 

 retaining its form and consistence, is quite black. On surface agar 

 a thick cream-coloured layer develops ; on potato the growth is 

 brownish, and milk is coagulated. It grows freely in broth and 

 peptone-water, the fluid becoming uniformly turbid, and a slight 

 film forms on the surface, and these cultures give a marked indole 

 reaction on the addition of sulphuric acid alone, in this respect 

 resembling the Koch vibrio. The S. Metchnikovi is pathogenic 

 to chickens, pigeons and guinea-pigs, but not to rabbits or mice 

 except in large doses. It is, however, more pathogenic to guinea- 

 pigs than the cholera vibrio. Pigeons are killed by intra -muscular 

 inoculation, and fowls are susceptible to feeding, whereas the 

 cholera vibrio is not pathogenic to fowls by feeding. It is not 

 agglutinated with cholera-immune serum. Abbott * isolated a 

 pathogenic spirillum from the Schuylkill River, Philadelphia, which 

 resembles the S. Metchnikovi closely, and is probably identical with it. 



Spirillum Finkleri (of Finkler and Prior) 



Isolated from the stools in certain cases of cholera nostras, but 

 its etiological significance is doubtful. It occurs as short, thickish, 

 curved or straight rods, and sometimes as spiral filaments. It is 

 aerobic and facultatively anaerobic, does not form spores, and does 

 not stain by Gram's method. In a gelatin stab-culture a yellowish 

 growth forms with rapid liquefaction (Plate XVIII. d). On agar a 

 thick, slightly brownish, moist layer develops. Serum is rapidly 

 liquefied. On potato a slimy brownish growth occurs even at 

 room temperature. It grows in broth and peptone -water, pro- 

 ducing a general turbidity. It does not as a rule give the indole 

 reaction with sulphuric acid alone, but the ordinary laboratory 

 cultures after three to four days' growth occasionally give a slight 

 reaction. It is stated to be pathogenic to guinea-pigs by intra- 

 peritoneal inoculation. 



1 Journ. of Exper. Med., vol. i, 1896, p. 419. 



