Regeneration and rate of growth of hairs in man

TLDR: The position of orifices of hair follicles was charted with reference to one to four small, permanent tattoos which were made in the skin with India ink withdrawing to scale as illustrated in FIGURE 1.

Abstract: The position of orifices of hair follicles was charted with reference to one to four small, permanent tattoos which were made in the skin with India ink. The tattoos were judged to be permanent if the ink could still be seen 48 hours after tattooing. At this time, the position of the tattoos and the orifices of follicles containing terminal hairs was drawn to scale as illustrated in FIGURE 1. Areas chosen for tattooing contained 6 to 12 hairs. The separately identified hairs were then plucked and preserved for microscopical study. A few hairs were observed to break upon plucking. If the stub could not be pulled immediately, it was removed after an interval of 7 days. Plucked areas were observed a t weekly intervals until the regeneration of hairs had been completed. A hair was considered to have regenerated when its tip projected above the skin. The time required for regeneration of a hair was calculated upon the number of days between plucking of an old hair and the appearance of a new hair above the skin, as observed a t intervals of 7 days. If a new