20 PRIMITIVE TREPHINING IN PERU [ETH. ANN. 16 
crania—a ratio probably higher than that of any modern military hos- 
pital, and scores or hundreds of times higher than that of the average 
cemetery of civilization. Most of the bolder operations of recent sur- 
gery are of modern invention, many of them reflecting (in successful 
practice at least) the career of a leader still living, Sir Joseph Lister; but 
trephining boasts an origin so remote, a lineage so long, an ancestry so 
eminent, as to claim a special place among the medical arts. It would 
be difficult to find a more striking illustration of the persistence of a 
remarkable custom throughout the stages of cultural development than 
that exemplified in trephining, and the example is of the first impor- 
tance in illustrating the development of the healing art with which it is 
connected. 
Reviewing the relations epitomized in the table, it may be noted par- 
ticularly that the practice of trephining has not only outlived the com- 
plete transformation in technology which accompanied the passage from 
stone to metal, but has survived all of the most profound intellectual 
revolutions in the history ef mankind. As a corollary of this striking 
proposition (which is fully established by the tacts summarized in the 
table), it may be noted particularly, also, that trephining was not orig- 
inally a curative treatment; indeed, the early practitioners had no con- 
ception of real curative or restorative treatment, no glimmering of 
physiologic or etiologic knowledge, no idea of relation between bealth 
and disease, no definite notions concerning the conditions of life and 
the causes of death. As a scholium to this corollary, it may be par- 
ticularly noted, finally, that the practice of trephining has survived 
transformation in motive and has persisted only through the gathering 
of new motives as knowledge has progressively grown up. 
Thus the history of trephining is complex, and it is not easy, from the 
standpoint of modern knowledge, to perceive how or why the practice 
was pursued in any generation or in any succession of generations 
before the development of scientific motives and refined methods. True, 
it may be stated as a general law—the verity of which is not generally 
recognized, though it may confidently be aftirmed—that, save sometimes 
in the modern stage of invention, men learn how and why they act only 
by acting, so that the action precedes its own explanation; yet even 
this law does not fully elucidate the origin of a peculiar, not to say 
monstrous, course of action, nor does it clearly indicate how such an 
operation, visibly accompanied by great suffering and often attended by 
loss of life, could have originated intelligently or could have persisted 
even if it originated accidentally. Manifestly the chief difficulty in the 
way of explaining the origin of trephining grows out of the fact that 
the operation was discovered and was long practiced before the motives 
actuating enlightened men were developed; and it follows that search 
for the origin of the operation can be hopefully conducted only in the 
light of knowledge of the motives of primitive men. Fortunately the 
way in which barbaric and savage people think is coming to be under- 
stood; and the light thus given illumines fairly, though at some points 
faintly, the wonderful course of development of the art of trephination. 
