BACILLI RESEMBLING TUBERCLE BACILLI IN STAINING 319 



strated in the sympathetic nervous system, in the spinal cord, and in 

 the brain. The bacillus lepne occurs also in the blood, partly free and 

 partly within the leukocytes, especially during the febrile stage which 

 precedes the breaking out of fresh tubercles (Walters and Doutrelepont). 

 The bacilli have also been found in the intestines, in the lungs, and in 

 the sputum, but not in the urine. 



With regard to the question of the direct inheritance of the disease 

 from the mother to the unborn child there is considerable difference of 

 opinion. Some cases have been reported, however, in which a direct 

 transmission of the bacillus during intrauterine life seems to be the 

 only or most plausible explanation of the infection. At the same 

 time, we have no positive experimental evidence to prove that such an 

 infection does take place. Although many attempts have been made 

 to infect healthy individuals with material containing the bacilli of 

 leprosy, the results are not conclusive. Even the experiments made by 

 Arning, w r ho successfully infected a condemned criminal in the Sandwich 

 Islands with fresh leprous tubercles, and which has been regarded as 

 positive evidence of the transmissibility of the disease in this way, is by 

 no means conclusive; for, according to Swift, the man had other oppor- 

 tunities for becoming infected. These negative results, together with 

 the fact that infection does not more frequently occur in persons exposed 

 to the disease, may possibly be explained by the assumption that the 

 bacilli contained in the tuberculous tissue are mostly dead, or much 

 more probably that an individual susceptibility to the disease is requisite 

 for its production. 



The widespread idea, before the discovery of the leprosy bacillus, 

 that the disease was associated with the constant eating of dried fish 

 or a certain kind of food, has now been entirely abandoned. 



The relation of leprosy to tuberculosis is sufficiently evident from 

 their great similarity in many respects. This is rendered still more 

 remarkable if the observation recently made is true, that leprosy reacts, 

 both locally and generally, to an injection of tuberculin in the same 

 manner as tuberculosis (Babes and Kalindero). 



Differential Diagnosis. The differential diagnosis between leprosy 

 and tuberculosis is not difficult in typical cases. The large numbers 

 of bacilli found in the interior of the cells would point with great prob- 

 ability to leprosy. Too much importance should not be placed upon 

 the staining peculiarities, as these are not constant. Moreover, the two 

 diseases not infrequently occur together in the same individual. In 

 making the diagnosis, therefore, all the signs, histological and patho- 

 genic, must be considered and animal inoculations made. 



Timothy and Other Grass Bacilli. 



On various grasses, in cows' manure, in butter, and in milk, there 

 have been discovered a number of varieties of bacteria which have 

 more or less of the characteristics of the tubercle bacillus. Some of 

 them are as difficult to stain and as resistant to the decolorizing action of 



