246 BACTERIA. 



the later stages of the disease. On the fingers the thickened 

 patches and ulcerations may extend so far and so deep that 

 part of the finger may be actually separated and thrown off, 

 first, however, becoming dry and black or mummified. The 

 patients may linger on in this condition for a considerable 

 length of time ; or the tubercles may disappe.ar, leaving dis- 

 coloured patches, in which sensibility is entirely wanting, and 

 which, in consequence, very rapidlyundergo ulceration,usually 

 brought on by injury, the patient, unable to feel, allowing the 

 parts to be injured without making any effort to save them. 

 The second form — anaesthetic leprosy — commences in much 

 the same way, except that the discoloured patches are somewhat 

 smaller, and may be red or brown ; in some cases the patches 

 have a peculiar glistening or silvery-white appearance. The 

 pigmented patches, which are often very widely distributed, 

 have, especially where they attain any very great size, a dull, 

 pallid centre, with a line of brown, or brown and red coloura- 

 tion, surrounding it. Some of the smaller spots are anaes- 

 thetic, whilst, in addition, there may be large areas in which 

 sensation is markedly diminished or altogether abolished; the 

 hair falls out ; there is marked atrophy of the skin and the 

 cellular tissue immediately beneath, this giving rise to a 

 very wrinkled appearance of the face ; and the patient, as in 

 the other kind of leprosy, becomes dull and heavy-looking, 

 as though he had lost all interest in external affairs. Here 

 also injury to the extremities is of very frequent occur- 

 rence, partly owing to the fact that the patient cannot feel, 

 but partly also, because the nutrition of the skin is markedly 

 interfered with. Other skin diseases, the formation of 

 vesicles, and so forth, are often met with. Either form may 

 gradually pass into the other, in which case we have what 

 are known as mixed varieties of the disease. 



In order to demonstrate the presence of the bacillus in 

 one of the nodules in a case of tubercular leprosy, it is only 

 necessary to tie an india-rubber ring somewhat firmly around 

 the base of one of them until it becomes pale from the blood 

 supply being cut off, and then, with a needle-shaped lancet 

 or the point of a sharp knife, to make a small puncture, 

 from which a clear fluid exudes. In this may be found an 

 enormous number of bacilli. These bacilli resemble the 

 tubercle bacilli in a most remarkable manner, the only 

 difference being that they are, if anything, slightly shorter. 



