386 MORBID ANATOMY OF THE SKIX. 



must tliereforc contain mucin. The ultimate result of these 

 changes is the texture represented in fig. 119, a, which may he 

 regarded as embr^^onic tissue of the most typical kmd.* So far 

 therefore, the leprous nodule, though distinguished from the 

 syphilitic product by its size and its occurrence in a multiple 

 form, agrees with it most absolutely in being composed of granu- 

 lation-tissue. The agreement is absolute in this respect until 

 retrograde metamorphosis sets in. The leprous product indeed, 

 like that of syphilis, undergoes disintegration by a combined 

 process of fatty degeneration and suppuration ; it differs from it 

 in the long period of its precarious quiescence. For v\'e may 

 fairly term the condition of a tissue precarious, when it contains 

 a vast number of elementary parts requiring nourishment, parts 

 which have taken the place of a parenchyma at once smaller in 

 bulk and containing fewer cells ; and this without any adequate 

 increase in the supply of nutrient material by a simultaneous 

 formation of nevv' vessels. Retrograde metamorphosis or suppu- 

 ration might be expected to set in at once. But neither of these 

 changes seems in any hurry to begin. At last, after years have 

 elapsed, the nodule becomes softer, its intercellular substance 

 undergoes partial liquefaction, some of the cells are destroyed by 

 fatty change ; but complete resolution can only occur if the 

 growth was very limited in extent. The nodule passes into 

 suppuration and ulceration only if it is exposed in an exceptional 

 degree to violence and other sources of external irritation. A 

 slight increase of cell-growth then converts the leprous nodule 

 into pus, which is evacuated externally, leaving a proportionate 

 loss of substance behind it. The leprous ulcer thus produced 

 continues to discharge a thin and sanious pus, which usually 

 dries up into brownish crusts. 



The same specific product of morbid growth underlies the 

 other disorders incidental to leprosy. Thus e.g. the cutaneous 

 anaesthesia is due to the growth of nodules upon the nerves ; the 

 spontaneous disarticulations of the limbs are caused on the one 

 hand by the gradual extension of the infiltration to deeper parts. 



* Hansen states (Nordiskt Medicidskt Arkiy. i., 13) that in the older 

 leprous tubercles, cells are found which contain, besides a nucleus, a 

 broTvnish oily spherule, together ^vith peculiar amorphous bodies of 

 large size which seem to be entirely made up of such spherules. 



