3M 3I0IIBID ANATOMY OP THE SKIN. 



secondary phenomenon. In e\'ery pustule of acne, we must 

 distinffuisli anatomically between the alterations in the central 

 hair-sac, and those in the surrounding connective tissue. The 

 root and root-sheath of the hair remain passive throughout, save 

 that a large number of epidermic cells in a state of fatty de- 

 fifcneration collect between them. All the more strikinoj is the 

 active part taken by the sac of connective tissue in the inflam- 

 matory process. It appears to be completely converted into 

 pus ; for in the matter squeezed from a ripe acne-pustule, I have 

 never found an}^ trace of it ; nothing but the hair, together with 

 the pus-corpuscles and epidermic cells ; and this although the 

 residual loss of substance is twice or three times as large as the 

 original hair-sac. The vessels of the follicle, owing to the 

 liquefaction of the connective tissue in which they lie, undergo 

 maceration ; the cells which line the sac appear to share in the 

 inflammatory proliferation, and the wails of the sac to lose their 

 cohesion in consequence ; for when the escape of the pus relieves 

 them from compression, they nearly always give way. 



The true seat of inflammation is the surroundino; connective 

 tissue of the cutis ; hypercnemia, plastic infiltration, and sup- 

 puration, following one another in an area extending from half a 

 line to two lines from the follicle. The pus collects round the 

 latter, and long before we can detect it shining through the 

 cuticle, a drop of it exists in the depths of the cerium, which 

 may be evacuated by a puncture {G. Simoii). It is not till a 

 later period, that the little abscess begins to point. The mouth 

 of the follicle opens very gradualh*, the bundles of connective 

 tissue which surround it yield very unwillingly. The pus-cells 

 burrow between them and tlie epidermic portion of the hair-sac, 

 and accumulate round the shaft of the hair, pushing the epi- 

 dermis before them. Finally, the process culminates in the 

 speedy rise of a somewhat abrupt, straw-yellow pustule. If the 

 pustule be punctured and kept from drjang up, it gradually 

 empties itself of its own accord. As a rule, a firm pinch expels 

 both the pus and the follicle which contains it. The proliferative 

 activity in the skin rapidly subsides thereupon ; the bundles of 

 connective tissue come tocrether ao^ain, and the little hollow 

 which was formerly occupied by the follicle is filled up with a 

 small quantity of cicatricial tissue. 



Sycosis is merely a variety of acne. While the latter is 



