C. M. Wen YON 
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size and does not ulcerate. The superficial layers may form into a dry 
scaly covering, which breaks away leaving a thin red skin beneath. If 
the scaly covering is forcibly removed, the skin may be broken showing 
a mass of red granulation tissue from which a pure culture of the 
parasite can be obtained. The granulations thus exposed soon scab 
over, and if left undisturbed the sore shows no tendency to further 
ulceration. Eventually the sore shrinks and becomes less elevated, till 
finally there is nothing left but a dusky red patch on the skin which 
gradually changes to a thin, white scai', very slightly depressed. The 
scarring left by the non-ulcerating male sores is never so extensive as 
that produced by the ulcerating variety in which the secondary bacterial 
infection has brought about a greater destruction of tissue. It must be 
remembered that the two types of sore just described are connected by 
intermediate forms, and a sore which has been progressing as a male 
non-ulcerating sore may suddenly break down and ulcerate. There is 
nothing in the character of the parasites to be obtained from the two 
types of sore that would lead one to suppose that there is any specific 
difference between them. 
It is veiy rarely that any deformity results from the contractions of 
the superficial scars or date marks. In the case mentioned above in 
which there was extensive ulceration on the face, the lower eyelid was 
completely destroyed, so that considerable deformity would be bound to 
result. But such a case is very exceptional. 
Duration of the disease. The duration of the disease is usuallj;'about 
one year with a variation of three months on either side of the limit. 
The advent of ulceration and the infection with extraneous organisms 
have little effect on the life of the individual sore. The male and female 
sores are of about equal duration. 
Immunity. It is a general rule that after the sore has healed and 
disappeared the person is protected completely from further attack. 
I have been told of persons who have had a second and even a third 
attack with several years intervening between each. If such cases occur 
they must be extremely rare. The consensus of opinion amongst the 
inhabitants of Bagdad is that a second attack is impossible. The fact 
that sores in adults who have always lived in Bagdad are never seen, is 
a sufficient proof that the infection of childhood has conferred a life long 
immunity. As mentioned above, it is frequently the ease that a second 
sore will commence during the course of the first. Such secondary sores 
may be simply an auto-iuvfection. As it is possible to inoculate the 
parasite by simple scarification in the presence of juice from a sore, it 
