fiEiciiEKi DIFFERENT BlETllODS OF TREPHINI^^G. U 



if not entirely, upon the young child, but one especially strikin-.' and 

 ingenious illustration which he founded upon a cranium discovered by 

 Pruni^res in the dolmen of Cibournios must be related. 



It is well known that the sutures of the skull tend to become firmly 

 united with the advance of years. In the young child the remains of the 

 sutural membrane still exist, and a separation is easy. In the accompau)'- 

 ing drawing it will be perceived that the left parietal bone has been operated 

 upon, and the resistance of the arch on that side being thereby diminished, 

 the right parietal has encroached considerably over the median line, in the 

 process of after growth, indicating the youth of the subject at the time of 

 the operation. (Plate V.) 



As regards the general harmlessness of the operation, there is a view 

 which must be suggested, in passing, which has not been considered before 

 in this connection, and that is the relation of race to traumatism. In other 

 words, the capacity to bear wounds or surgical operations, or the contrary, 

 dependent not on individual but on race characteristics. Long ago, Velpeau 

 said that French flesh and English flesh were quite diff'erent, and opera- 

 tions that were generally successful in the one were frequently f;ital in 

 the other. The subject is of inuiiense extent, requiring copious observa- 

 tions, which should include toleration of child-bearing, before any conclu- 

 sions can be reached. It will be seen presently that the Arab tribes who 

 practice trephining regard it as almost without danger. It is possible that 

 race is to be regarded as a factor in the calculation of the results of tre- 

 phining. 



Some account must now be given of the probable manner of proceed- 

 ing in prehistoric trephining. 



There are three processes by which an opening in the cranium can be 

 methodically produced — by rotatory movement, by cutting, and by scraping. 



The most perfect example of the first-named method is in the use of 

 the modern trephine, which consists of a steel cylinder with saw-teeth and 

 a central pin to guide its first motion; the Avhole being worked by a cross- 

 handle like that of a gimlet This instrument cuts out a circular piece of 

 bone, leaving a corresponding aperture with perpendicular edges. The first 

 foini of the trephine dates back to the early days of Greek surgery; cer- 



