ILLUSTRATIONS 



Plate I 



Fig. 1. Early lesion, duration six weeks. Before ulceration. Consider- 

 able undermining of skin with but a small sinus. Case V. 



2. Ulcers of wrist; upper lesion unusually active, duration one month; 



lower lesion several months. Scar in palm from previous lesion. 

 Case II. 



3. Spreading lesion on dorsum of same hand, same case. Duration 



about one year. ' 



4. Lesions of leg, case III. Irregular ulcer on inner surface of foot 



marks the site of a smooth swelling, skin intact, seen three 

 months previously. 



5. Original lesion, case III. Involvement of bone with some shorten- 



ing of toe. Duration about fifteen months. 



6. Lesions of leg, case IV. Full extent of tissue loss not apparent at 



the angle shown. Duration at least two years. 



Plate II 



Fig. 7. Section from advancing edge of leg ulcer, case IV (see fig. 6), 

 showing hyperplasia and canalization of epidermis, with absence 

 of infiltration. X 11. 



8. Similar section from case I. Thinning of epidermis at edge of 



ulcer evidently secondary to inflammatory lesion below. X 12.5. 



9. Endothelial proliferation in small blood vessel, without infiltration. 



X 300. 



10. Tuberclelike focus apparently marking site of small vessel, x 300. 

 (Figs. 9 and 10 from same section as fig. 7.) 



11. Vessel in center shows both proliferation and early leucocytic in- 



filtration. X 180. 



12. Focus of endothelial cells, with a few leucocytes, apparently re- 



sulting from obliteration of a vessel. X 180. 



13. Vessel on left contains red blood cells; lumen of that on right 



almost obliterated; that in center obliterated by a thrombus 

 containing small, deeply stained granules and fragments, x 180. 



14. Area of small vessels with considerable leucocytic infiltration. 



Deeply stained granules (nuclear fragments?) and shreds are 

 prominent. X 180. 



Plate III 



Fig. 15. Area somewhat similar to fig. 14. X 300. 



16. Large (mitotic endothelial?) cell seen in lower part of fig. 15. 



X 650. 



17. Group of six Langerhans's giant cells. X 300. 

 (Figs. 11 to 17, inclusive, from deep tissue, case III.) 



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