STONE AGE' SKULL SURGERY — STEWART 483 



surgical tools, but for a long time these new tools lacked the neces- 

 sary hardness and sharpness. Probably accessory objects of perish- 

 able materials, such as wood, cloth, etc., were used also, but little, if 

 anything, is known about them, except in areas where the practice has 

 persisted. 



Like the surgeons' implements of perishable materials, the soft 

 parts covering the prehistoric skulls have disappeared where they 

 have not mummified. On page 470 the writer mentioned his earlier 

 demonstration of the fact that the extent of the openings of the scalp 

 made by ancient Peruvian surgeons prior to opening the skull some- 

 times is still imprinted, so to speak, on the bone (mainly in connection 

 with rectangular trephine openings) . This record is due to the fact 

 that in Peru the surgeons often removed the scalp completely over 

 the area where they planned to trephine, and in so doing they made 

 their incisions in an angular pattern so that the opening in the scalp 

 had three to five or more sides (but commonly only four). The im- 

 printing of this event on a skull could come about in several ways: 

 Postoperative bone infection could begin at the margins of the wound 

 where the blood supply was cut off and gradually undermine the 

 exposed outer table; or the infection could clear up and new bone 

 form with a pattern of scarring conforming to the preceding pat- 

 tern of infection ; or, in the event the patient died during the opera- 

 tion, the soft parts could mummify, leaving the bone exposed by the 

 surgeon to be discolored differently from that covered by scalp 

 (either darkened by chemical dyes or bleached by sunlight). Plates 

 9 and 10 illustrate clearly these alternatives (see also figs. 3 and 5 in 

 Stewart, 1956). No longer is it sufficient to look at the trephine 

 openings alone ; all the surrounding bone must be inspected for clues 

 as to what happened. For example, plate 9, lower left, shows one of 

 many cases of surgery on the forehead in which the incisions through 

 the scalp were in a diamond-shape pattern with long axis running 

 anteroposteriorly. Probably this shows a knowledge of the tensions 

 in the scalp. 



In the fairly large number of Peruvian cases where death occurred 

 during or immediately after the trephining, and the soft parts did 

 not mummify, there is, of course, no way of knowing the size of the 

 opening in the scalp. However, accidental cut marks on the bone 

 beyond the limits of the opening sometimes suggest where the scalp 

 incisions were placed. Again, in the fairly large number of cases 

 where bone healing followed trephining without leaving much scar- 

 ring and certainly no angular pattern of scarring, it is assumed that 

 the edge of the scalp opening was near the edge of the opening in the 

 bone, or possibly small scalp flaps were replaced over the opening. 

 Perhaps such a technique was used in Europe in ancient times. In 

 Melanesia the skin flaps were replaced and then stitched (Ford, 1937) . 



