416 BACILLI IN CHRONIC INFECTIOUS DISEASES. 



mation has not been definitely settled. As before remarked, un- 

 stained portions, occurring at regular intervals, are seen in the rods in 

 stained preparations ; but no satisfactory evidence has been presented 

 to show that these are truly reproductive spores. 



Pathogenesis. The inference that the bacillus above described 

 bears an etiological relation to the disease with which it is associated 

 is based upon the demonstration of its constant presence in leprous 

 tissues which has now been repeatedly made in various and distant 

 parts of the world and of its absence from the same tissues involved 

 in different morbid processes. As it has not been obtained in pure 

 cultures, the final proof of such etiological relation is still wanting. 

 We have, however, experimental evidence to show that leprous tis- 

 sues containing this bacillus are infectious and may reproduce the 

 disease. The experiment has been made upon man by Arning, who 

 inoculated a condemned criminal subcutaneously with fresh leprous 

 tubercles. The experiment was made in the Sandwich Islands, and 

 the man was under observation until his death occurred from leprosy 

 at the end of about five years. The first manifestations of the disease 

 became visible in the vicinity of the point of inoculation several 

 months after the experimental introduction of the infectious material. 



Positive results have also been reported in the lower animals by 

 Damsch, by Vossius, and by Melcher and Ortmann. The last-named 

 investigators inoculated rabbits in the anterior chamber of the eye 

 with portions of leprous tubercles excised for the purpose from a 

 leper. The animals died from general infection at the end of several 

 months, and the characteristic tubercles containing the bacillus were 

 distributed through the various organs. 



Wolters (1893) who has made numerous inoculation experiments 

 and has made a critical review of all the recorded experimental evi- 

 dence, arrives at the conclusion that the comparatively small number 

 of successful results reported cannot be accepted as evidence that 

 leprosy can be transmitted to the lower animals by inoculation. He 

 believes that in some cases the tubercle bacillus has been present in 

 the material inoculated and that the infectious process following the 

 inoculation was tuberculous and not leprous. In inoculations into 

 the anterior chamber, in the eyes of rabbits, the considerable number 

 of bacilli introduced with the leprous tissue remain and retain their 

 staining properties, so that the bacilli originally introduced are found 

 in the leucocytes of the inflammatory exudate or granulation tissue 

 formed as a result of the introduction of foreign material. Wolters 

 also doubts whether the few successful results reported in the culti- 

 vation of the lepra bacillus are trustworthy. He has never succeeded 

 in his efforts to cultivate the bacillus. 



