Gross and microscopic observations of graft and surrounding area were made after grafting during various stages of the hair growth cycle.

All grafts were successful although temporary disturbance was observed when grafting was done during late anagen.

Biopsies showed epidermal breakdown, even in telogen grafts, with repair being accomplished primarily by diversion of hair follicles to epidermal production. The later in anagen a graft was done, the less likely the follicles were to return to hair production later.

Permanent loss of pigment was seen in some grafts, particularly those done in late anagen. Loss of pigment cells or their attachments from scraping the graft undersurface is a possible explanation, as is loss or damage to melanocytes while the follicles are producing epidermis.

Delays and irregularities in hair growth cycles were also observed in host skin surrounding grafts. An explanation involving loss of inhibitor during grafting is proposed.

The authors feel that hair growth activity in either donor or host is not an adequate explanation for graft rejection. It is also emphasized that hair growth is a poor criterion for graft survival.