60 PRIMITIVE TREPHINING IN PERU [ETH. ANN. 16 
In some eases the size of the instrument used for rasping is roughly 
indicated. The grinding out of the kerf terminals in crania 7 (the later 
operation) and 18 (the latest operation) produced surfaces curved in 
two dimensions, of such degree of curvature as to indicate that the 
instrument must have been about the size of the blade inferred from 
the incisions; moreover, in cranium 16 the strive traversing the fracture 
terminate anteriorly in a series of scratches precisely such as accom- 
pany the kerf terminals, suggesting that in this instance, at least, the 
strise were produced by the distal portion of a blunt-point instrument 
corresponding generally to the incising tool. 
Accordingly, there is a fairly conclusive body of evidence that the 
rasping was effected by means of common stone implements, either 
identical with or closely similar to those used in cutting, and there are 
no marks which might not be produced by such an instrument, nor is 
there the least indication that instruments of metal, tooth, or shell 
were employed, though it is possible that some of the work (e. g., in 
cranium 10,in which the traces of instrumentation are practically oblit- 
erated) might have been performed with other materials than stone, the 
scraping of the South Sea islanders being suggested. 
In the single case in which the bony fulerum of the elevator is dis- 
tinctively preserved cranium 4), the marks indicate merely that the 
instrument was rough or irregular, rather than smoothly rounded, sug- 
gesting that the elevator was nothing more than the stone blade used 
in making the incision. In several cases, however, there are indications 
that considerable force was exerted in raising the butto.a, perhaps 
requiring a tougher material than stone, which suggests that special 
instruments of tooth, antler, or hard wood might have been employed 
for this purpose. 
It may be noted in passing that the Squier cranium corresponds in 
indications of instrumentation with crania 1 and 3 of the Muniz collec- 
tion, while several of the Cuzco crania indicate the employment of 
dissimilar methods and distinct instruments; but in the absence of 
decisive facts, such as can be obtained only by critical examination 
of the specimens themselves, these examples of Peruvian trephining 
may be passed over without detailed consideration. 
Summarily it appears that the instruments used in performing the 
operations exemplified in the Muniz collection were chiefly or exclu- 
sively stone implements of the character found among nearly all primi- 
tive peoples, including the ancient Peruvians. There is nothing to 
indicate that the instruments were in any way specialized; there is 
absolutely no indication of the employment of trephines, saws, or other 
multiple-point instruments, aud only negative suggestions concerning 
the use of metal. 
