450 INFECTIVE DISEASES. 



colour and becomes a dull white. The growth is very adherent to 

 the surface of the jelly, and so tough that it is almost horny. The 

 Streptothrix can he cultivated in milk, which it slowly pepto- 

 nises. It cannot be grown on blood serum or egg. On potato, on 

 .the fifth day at 37° C, there are little prominent colonies, which 

 slowly increase. After a month the growth acquires a pale-rose 

 colour, which gradually increases and changes to orange or dark 

 red. The colour is most intense on acid potato, and after a time 

 an efflorescence, or whitish dust, appears on some of the colonies, 

 consisting of spores. The growth is hard and friable. 



Rabbits, mice, guinea-pigs, and a cat, were inoculated sub- 

 cutaneously with particles from the disease, or with cultures ; but 

 only a local nodule was produced in each case, which, after a shght 

 increase, subsided. Nocard confirmed these results. Intra-peritoneal 

 and intravenous and subcutaneous inoculations in guinea-pigs, rabbits, 

 pigeons, .fowls, dogs, and sheep were negative; and no trace could 

 be found of the cultures in any animal subsequently killed and 

 examined. According to Bocarro, though fresh particles from the 

 disease inoculated in rabbits and dogs gave negative results, inocu- 

 lation of cultures in guinea-pigs, rabbits, monkeys, and rats, pro- 

 duced a local tumour of slow growth, which, on section, had the 

 character of the inoculated material. 



From these experiments we must conclude that the disease has 

 not been shown to be transmissible to the lower animals, by either 

 inoculation of the diseased tissue, or by cultures of the Streptothrix ; 

 and the exact relation of both the Streptothrix and the mycehal 

 fungus to the disease must be considered an open question. 



