VIBRIO PROTEUS. 363 



verted into a cloudy fluid, whereas at the lower part of 

 the canal the liquefaction progresses less rapidly but is 

 still much more marked than that seen as a result of 

 the growth of Koch's spirillum. Indeed, under these 

 circumstances there is no similarity whatever between 

 the growth of the two organisms (see a, 6, c, d, Fig 70, 

 and compare these with corresponding cuts in Fig. 67). 



It is customary to see, scattered through the cloudy 

 liquefied gelatin, ragged, more or less dense masses, 

 fragments of the colony proper. 



On nutrient agar-agar there is nothing particularly 

 characteristic about its growth, appearing only as a 

 moist, grayish or yellowish -gray deposit. 



On potato, after forty-eight to seventy-two hours, there 

 appears a pale, yellowish-gray deposit; this is moist, 

 glazed, and marked by lobulations, and is surrounded 

 by an irregular, colorless zone of growth that is much 

 less moist than that forming the central area. It grows 

 well on potato at the ordinary temperature of the room. 



It causes liquefaction of solidified blood-serum and of 

 coagulated egg albumin. 



In milk to which neutral litmus tincture has been 

 added the blue color takes on a pink tinge in from two 

 to three days at 37 to 38 C. 



It does not form indol nor does it cause fermentation 

 of glucose. 



In peptone solution containing rosolic acid, the color 

 is somewhat deepened after four or five days at 37 C. 



EXPERIMENTS UPON ANIMALS. By ordinary methods 

 of inoculation this organism is without pathogenic pro- 

 perties. Injections, subcutaneous and intra-vascular 

 and directly into the stomach, give negative results. 

 When introduced into the stomach of guinea-pigs by the 



