﻿470 MARSHALL. 



and staining properties. (See Pis. I and II, figs. 1 c; 2 h; 3.) Cross 

 sections through an epithelial downgrowth or hair follicle with central 

 softening, may be slightly suggestive of the "pearls" of epithelioma. 

 (See Pis. I and III, figs. 1 ej 2 c; 4.) Charlouis, Unna, and others note 

 especially that the hair follicles and hair shafts are unaffected, but this 

 does not hold true of the nodules now under consideration. The sections 

 from the human case did not pass through any hair follicles, but in the 

 sections from monkeys, hair follicles are abundant and the outer root 

 sheath shows exactly the same necrotic changes as are met with in the 

 other epithelial structures. The sweat glands and sebaceous glands are 

 altered less than the hair follicles and downgrowths. 



(b) The vascular and exudative changes .are marked in the corium, 

 and extend only a short distance into the heavier strands of subcutaneous 

 tissue. There is a very great dilatation of the capillaries extending to the 

 under surface of epithelium. Many capillaries are empty, others contain 

 polymorphonuclears, eosinophiles and a few mononuclears, while others 

 are full of erythrocytes. At first sight it appears as if most of the 

 erythrocytes are free in the tissue, but in my sections I have been able 

 to make out a limiting capillary wall in most cases and find only small 

 extravasations. The corium is markedly cedematous, the oedema ex- 

 tending into the epithelium and for a slight distance into the sub- 

 cutaneous tissue. The early yaws papule contains many leucocytes and 

 the ulcerating nodule is packed with them. A few polymorphonuclears 

 are found in the epithelial structures, while the downgrowths and other 

 degenerating parts are surrounded with collections of polymorphonu- 

 clears, large and small mononuclears, many of which are plasma cells, 

 with occasional eosinophiles. A few ^Tnphocytes are found and only a 

 small number of extravasated erythrocytes. The eosinophiles have poly- 

 morphous nuclei. The leucocytes are also found both within capillaries 

 and surrounding them, and it is most probable that they have arrived 

 by way of the blood vessels and have wandered out from them. The 

 distribution of eosinophiles is interesting. At the edge of the nodule, 

 beyond the line of epithelial degeneration and at a point where the 

 oedema and leucocytic infiltration is not very great, the number of 

 eosinophiles is both relatively and absolutely greater than it is beneath 

 the center of the lesion where the infiltration is denser. The eosinophiles 

 vary from 9 to 35 in one field of the microscope (Zeiss DD objective, 

 J^o. 3 eyepiece). They are scattered diffusely, but occur in greater 

 numbers around and in the dilated capillaries. (For exudative changes 

 see Pis. I and II, figs. 1, 2, 3.) At no point is there any evidence of 

 the perivascular infiltration with mononuclears, which is so characteristic 

 of syphilis. 



(c) Eegenerative changes. There is indication of slight new forma- 

 tion of capillaries in the corium and of a minor degree of connective tissue 



