''"'T^""="l BKOCA'S CONOLUSIONy— ON WHAT J3A8ED 7 



and of the sections of the skull was due, not to artificial iiolishing, but to 

 a process of natural cicatrization, which must necessarily have taken place 

 during life, and, indeed, many years before death. (Plate II.) 



After examination of a great many other specimens, Broca finally 

 announced two conclusions as the result of his investigations: 



I. In the neolithic age, a surgical operation was sometimes performed 

 for the cure of certain internal maladies, which consisted in making an open- 

 ing in tlie skull. This was almost, if not quite, exclusively practiced on 

 young children, and is to be termed prclmtork surgical trepJiining. 



II. The skulls of those who survived this operation were supposed to 

 possess some remarkable qualities, and when the owners died, amulets or 

 rondelles, consisting of portions of the skull, were carefully cut out. By 

 preference, the portion should contain a segment of the original aperture. 

 This was 2)ostliuinous trepliimng:' 



A concise account must be given of the evidence upon which these 

 conclusions were based. 



To the practiced eye there is no difficulty whatever in distinguishing 

 between a section of bone which has not been followed by any reparative 

 process and one in which that ]3rocess has gone on to completion. In 

 the first case, the edges are sharp, the cells of the diploe are open, and the 

 action of the cutting instrument is seen in the successive cuts by which the 

 operation has been performed. It is not uncommon to find scratches on the 

 surface of the bone, indicating where the tool had slipped away from the 

 intended incision. (Plate I, fig. 3.) 



When cicatrization of a ti-ephined or fractured skull has been perfected, 

 the edges present a rounded, ivory-like surface, due to the new osseous tissue 

 deposited in the cells of the diploe and upon the edges of the outer and 

 inner tables. 



But while it is easy to discriminate between a post-mortem incision and 

 one long since healed, it would be very difficult to decide that the incision 

 might not have been made during life, but shortly before death. The pro- 

 cess of repair in bone is much slower than in softer tissues, and it has been 

 suggested that the cases of so-called posthumous trephining were really 



= Siir la tr^pauation dii crano, etc., p. 9. 



