158 Lectures on Bacteria. [^ 



XIII. 



the careful observations of the latter author leave no room for 

 doubt. The introduction of the Coccus from a pure culture 

 into the eye of a new-born rabbit by Hausmann, and into the 

 eye and urethra of a human subject by Bockhardt and Bumm, 

 communicated the infection. It appears from Bumm's obser- 

 vations on the conjunctiva of the human eye, that the Micro- 

 coccus penetrates between the epithelial cells into the papillary 

 body of the mucous membrane, multiplies and spreads in these 

 spots and later also in the purulent secretion, and is ultimately 

 stopped in its further advance and got rid of by regeneration of 

 the epithelium and secretion of pus. The case examined by 

 Bockhardt showed more complicated phenomena. Bumm's 

 excellent monograph should be consulted for the details. 



I have put together relapsing fever, tuberculosis, and gonor- 

 rhoea, different as they are from one another, because if we 

 once put the doubts and the gaps in our knowledge on one side, 

 and take probability for certaintj', they supply us with examples 

 of actual obligate parasitic Bacteria. 



Spirochaete Obermeieri is, as far as we at present know, 

 strictly obligate, inasmuch as it can only be conveyed from one 

 person to another without digression into saprophytism, and is 

 confined to men and apes. 



The BacUlus of tubercle and Gonococcus may certainly be 

 cultivated as saprophytes, a facultative saprophytism cannot be 

 denied them. But this character can scarcely be taken into 

 consideration in their case ; not in that of the Bacillus of tubercle, 

 as Koch urges, because the conditions of its vegetation as a 

 saprophyte are of such a kind and so limited, that they will 

 scarcely ever be found except in an apparatus contrived for the 

 special purpose, nor yet in that of Gonococcus for similar 

 reasons. This follows at once from our experience in 

 general, and it follows further that the resisting power of 

 the Gonococcus is very small, and its dissemination for the 

 purpose of infection, as for example in dust after desiccation, 

 is not worth consideration. Gonorrhoeic affections are scarcely 



