VIBRIO PROTEUS. 477 



under these circumstances there is no similarity what- 

 ever between the growth of the two organisms. (See 

 a, h, e, d, Fig. 81, and compare them with correspond- 

 ing cuts in Fig. 78.) 



Ragged, more or less dense masses, fragments of the 

 colony proper, are usually seen scattered through the 

 cloudy liquefied gelatin. 



On nutrient agar-agar there is nothing particularly 

 characteristic about its growth, appearing only as a 

 moist, grayish or yellowish-gray deposit. 



On potato a pale, yellowish-gray deposit appears ; 

 after forty-eight to seventy-two hours this becomes 

 moist, glazed, and marked by lobulations, and sur- 

 rounded by an irregular, colorless zone of growth 

 that is much less moist than that forming the central 

 area. It grows well on potato at ordinary room-tem- 

 perature. 



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 assumes a pink tinge in from two 

 to three days at 37° to 38° C. 



It does not form indol. 



It does not 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. — The ordinary meth- 

 ods of inoculation show this organism to be without 

 pathogenic properties. Injections, subcutaneous and 

 intravascular and directly into the stomach, give nega- 

 tive results. When introduced into the stomach of 

 guinea-pigs by the method employed by Koch in his 

 cholera experiments, Finkler and Prior had 3 out of 



