2 7 2 



EVOLUTION AND DISEASE. 



Leprosy is distinguished anatomically by the forma- 

 tion of nodules or tubercles in the skin, mucous mem- 

 branes and underlying tissues. When the skin is affected 

 the hands, feet, and face are most frequently attacked. 

 The nodules commence as red spots in the skin, which 

 become gradually of a blue tint, then brown : the sub- 

 jacent tissue becomes thick and hard. The tubercle 



FIG. 135. The face of a Leper. (After Ziegler. 



increases and forms a sub-globular, soft, pale-coloured 

 prominence, which, when knocked or rubbed, may 

 ulcerate. Leprous ulcers are commonest on the inside 

 of the nose, on the conjunctiva, and mucous membrane 

 of the larynx. When the nodules form on nerve sheaths 

 anaesthesia is produced. 



Microscopically, leprosy nodules are found to be made 



