272 LEPROSY. 



are also found, though in relatively smaller numbers. In the 

 nerves in the anaesthetic form they are comparatively few, and 

 in the sclerosed parts it may be impossible to find any. There 

 are few also in the skin patches referred to above as occurring 

 in this form of the disease. 



Their spread is chiefly by the lymphatics, though distribution 

 by the blood stream also occurs. They have been said to be 

 found in the blood during the presence of fever and the erup- 

 tion of fresh nodules, and they have also been observed in the 

 blood-vessels post mortem, being chiefly contained within leu- 

 cocytes. Recent observations {e.g. those of Doutrelepont and 

 Wolters) show that the bacilli may be more widely spread 

 throughout the body than was formerly supposed. A few may 

 be detected in some cases in various organs which show no 

 structural change, especially in their capillaries. The brain 

 and spinal cord are practically exempt. 



Relations to the Disease. — Attempts to cultivate the leprosy 

 bacilli outside the body have so far been unsuccessful. From 

 time to time announcements of successful cultivations have been 

 made, but one after another has proved to be erroneous. A 

 similar statement may be made with regard to experiments on 

 animals. If a piece of leprous tissue be introduced subcuta- 

 neously in an animal, such as the rabbit, a certain amount of 

 induration may take place around it, and the bacilli may be 

 found unchanged in appearance weeks or even months after- 

 wards, but no multiplication of the organisms occurs. The 

 only exception to this statement is afforded by the experiments 

 of Melcher and Orthmann, who inoculated the anterior chamber 

 of the eye of rabbits with leprous material, the inoculation 

 being followed by an extensive growth of nodules in the lungs 

 and internal organs, which they afflrmed contained leprosy 

 bacilli. It has been questioned, however, by several authorities 

 whether the organisms in the nodules were really leprosy 

 bacilU, and up to the present we cannot say that there is any 

 satisfactory proof that the disease can be transmitted to any of 

 the lower animals. 



It would also appear that the disease is not readily inoculable 

 in the human subject. In a well-known case described by 

 Arning, a criminal in the Sandwich Islands was inoculated in 

 several parts of the body with leprosy tissue. Two or three 



