264 The Philippine Journal of Science 1923 



complete. One still undetermined point is how the secondary 

 lesions begin and where they begin— whether in the corium or 

 in the epidermis. 



Practically all the histological studies of human material have 

 evidently been made with lesions from the eruptive stage of the 

 disease following primary local infection. There can be no 

 reasonable doubt that this exanthem is due to the localization in 

 the skin (2) of treponemata from the circulating blood entering 

 through the mother yaw. Whether they pass through capillaries 

 and papillae into the epidermis without obvious effect and there 

 proliferate, injuring surrounding tissue, or whether their initial 

 growth with primary inflammatory reaction is in the perivas- 

 cular tissue of the papillae with secondary invasion of the epi- 

 dermis is uncertain. 



Charlouis,(3) describing in 1881 the histology of a pinhead- 

 sized papule, thought the primary changes occurred in the co- 

 rium. He described a dilatation and tortuosity of the superficial 

 plexuses and then of the deeper vascular plexuses accompanied 

 by a diapedesis of leucocytes, an elongation of the papillae, and 

 an infiltration of granular cells between the fibers of the corium. 

 Pontoppidan(7) in 1882 placed the primary seat of the affection 

 in the prickle-cell layer of the epidermis. Macleod(4) in 1901 

 carefully described several stages of the eruption and concluded 

 that in the earliest skin manifestation which, following Nicholle, 

 he called the "squame," the initial stage occurred in the super- 

 ficial layers of the corium as was evidenced by a slight dilatation 

 and tortuosity of the papillary and subpapillary vessels in the 

 neighborhood with a marked extravasation around them of 

 leucocytes which passed therefrom into the lymphatic spaces 

 between the fibrous bundles and eventually reached the epi- 

 dermis. In 1907 Schuffner (9) demonstrated Treponema pertenue 

 for the first time in sections, by the silver method, and 

 found the organisims only in the epidermis. Later investiga- 

 tions (6, 10, 8) have confirmed this observation on the limited 

 distribution of the organisms, and Siebert(ll) is of the opinion 

 that they proliferate only there, because of the activity of cocci 

 from the surface which stimulate a local leucocytic exudate 

 favorable for their growth. In some of my preparations, as 

 will be described later, treponemata were demonstrated in great 

 numbers in the perivascular tissue about the terminations of 

 papillae; for this and other reasons it seems probable that the 

 secondary yaw begins with a lesion in the papillae and spreads 



