—_—— 
97 
of the cells about the blood vessels. Cocci and a few bacilli, together with much 
granular material and many degenerating cells, are distinguishable in the abscess 
cavity. 
As a result of this study the etiology of the human lesion in this case 
must remain obscure, at least, so far as the discovery of any single specific 
organism is concerned. Attention may again be called to the fact that no 
protozoa were encountered in the sections. That the Proteus bacillus and 
the Staphylococcus aureus, occurring in symbiosis, alone were responsible 
for the original lesion seems unlikely. However, there can be little doubt 
that these bacteria modified and caused an extension of the disease process. 
It is possible, even if not probable, that the organism responsible for the 
initial lesion in this case had already disappeared from the ulcer when 
T had the opportunity of examining it. 
ULCERATION OF THE THIRD TYPE. 
The third type of ulceration was observed in three cases—the first in 
a teamster, the second in a mechanic employed in an iron foundry, and 
the third in a male nurse. All of these were white men. 
Although I have been unable to discover the specific organism for this 
affection, it evidently varies both in its origin and nature from the two 
forms of ulceration already described. For this reason, as well as on 
account of the peculiar type of the lesions, it has been thought of impor- 
tance to call attention to them and to describe the cases somewhat in 
detail. In all three the ulcerations were multiple and were situated on 
the hands and forearms. In only one of the cases did the lesions occur 
elsewhere; in this instance they were situated on the feet and ankles; 
although they were not present here at the time I was able to study the 
case. Figs. 19 and 20 very well represent the distribution of the lesions 
in two of the cases. There were no general disturbances and there was 
very little or no itching. The lymphatic glands in the region of the elbow 
were the only ones which were swollen, and these were very slightly 
enlarged. One of the most striking features of the affection is its extreme 
chronicity. The disease usually commences by the formation of several 
small vesicles, which sometimes break and later form superficial ulcera- 
tions. In other cases, the vesicles become pustular before opening through 
the surface of the skin. Areas of fresh infection seem to occur from the 
older lesions, though I have not been able to entirely verify this fact from 
a microscopical study of sections. The ulcerations, as a rule, are shallow 
and but slightly painful; their margins are smooth; they do not have a 
punched-out appearance and they are not undermined. Their edges are 
reddened but not indurated. The skin for about 1 or 2 centimeters sur- 
rounding the ulcer is also erythematots. There seems to be little 
tendency for thick crusts to form, but small, soft, yellow scabs are 
frequently seen scattered over the surface. There is but little dis- 
charge; when it occurs it is usually of a serous nature. After several 
36512—7 
