BACTERIUM LACTIS AEROGENES. 335 



Bacterium lactis aerogcnes (Escherich). 



This organism was found, along with the previous A second 

 one, in the faeces of infants. It consists of short Sfeft^es'S 11 

 generally constricted rods with rounded ends, on an infants, 

 average 1*4 to 2 /*. in length, and *5 /*. in breadth, as a 

 rule occurring singly either as rods constricted in 

 middle, or as pairs of rods ; not motile. These organisms Cultivations, 

 grow on nutrient jelly like the pneumonia bacteria; in 

 plate cultivations they form round colonies, which spread 

 on the surface and form raised points of a porcelain white 

 colour. In puncture cultivations they grow luxuriantly 

 along the track of the needle, the needle track being 

 filled with a number of small white spheres arranged 

 like a string of beads with, at the upper part, a knob- 

 like swelling ; at the surface the colonies show a limited 

 growth, arched like the head of a pin, and of a soft con- 

 sistence. On potatoes they form a whitish-yellow creamy 

 layer full of gas bubbles. Milk coagulates with the for- Formation 

 mation of lactic acid in the course of 36 to 48 hours, at lactic acid ' 

 the ordinary temperature ; in solutions of milk sugar 

 and grape sugar the organisms cause intense fermenta- 

 tive action. In sugar solutions they appear to form 

 terminal spores. When sugar is present the bacteria 

 are also able to grow when oxygen is excluded, and at the 

 same time to cause fermentation, while without sugar 

 they cannot live in the absence of oxygen. Experiments Need for 

 on animals gave the same result as with the species oxygen - 

 previously mentioned, but the action was somewhat less 

 intense. 



Bacillus Neapolitans (Emmerich). 



A bacillus which appears to belong to this group of Bacillus found 

 bacteria was isolated by Emmerich* during the epidemic 

 of cholera in Naples, in 1884, from the organs, and 

 later from the intestinal contents of patients who had nad died of 

 died of cholera. This organism presents the form of c 

 short rods, with rounded ends, about '9 p.. in breadth, 



* Emmerich, Arch. f. Hygiene, vol. iii., 3 & 4 Heft. Buchner, ibid. 



