1904 Stöhr

 
Entwicklungsgeschichte des Menschlichen Wollhaares. Anat Hefte Abt. 1904;XXIII:3-66 (Fig. 5).

View Figure  		Fig. 5  [Fig. 14] Tangential view of a germinal cone, tip of the inner root sheath, m. arrector, sebaceous gland, outer root sheath, undifferentiated cells of the hair cone, bulge, glassy membrane, papilla. (Reproduced with permission.) Key: Tangentialschnitt eines Haarzapfens = secondary hair germ; Spitze der inneren Wurzelscheide = tip of inner root sheath; Talgdrüse = sebaceous glands; Äussere Wurzelscheide = outer root sheath; Indifferente Zellen des Haarkegels = hair cone; Wulst = bulge; Glashaut = vitreous membrane; Papille = papilla; M. arrector = arrector pili muscle
 

Message

 
"The bulge" develops independent of any pull upon it of a musculus erector pili.
 
"The bulge" does not give rise to a new follicle. Its function is to facilitate retraction of a club hair during a follicular cycle.
 
The outgrowths that constitute "the bulge" are pathologic.
 

Critique

 
Stöhr denied that "the bulge" functions as the source of cells for a new follicle, but he did not propose an alternative explanation for the reservoir of them.
 
"The bulge" plays no role in the ascent of a club hair. A club hair comes to rest (telogen) at the base of the isthmus.
 
Bulges, i.e., protuberances of isthmic epithelium, contrary to the views of Unna and Stöhr, are normal, not pathologic.