48 PRIMITIVE TREPHINING IN PERU [ETH. ANN. 16 
The second aperture would seem to have been produced by a single 
operation, probably subsequent to the principal one. It was evidently 
begun by a rectilinear incision of the usual character, commencing at 
a point over the temporo-parietal suture (subsequently removed by 
the conspicuous canoe-shape incision) and below the main aperture, and 
extending thence forward at least 15 mm. to the main vertical fissure 
and probably somewhat farther. It was not carried through the bone. 
There are indications that when the bone was weakened by this incision, 
an elevator was used to break out two or more fragments, thus pro- 
ducing the triangular aperture. Jagged projections of the inner por- 
tion of the bone remained and were not removed, but the outer edges 
were smoothed by rasping or scraping. 
The next operation or step produced a single rectilinear incision 35 
min, in length, 5 mm. wide at the center measured on the outer surface, 
of the usual V-shape section and terminations, penetrating the bone for 
a length of 11 mm. and a width of 2 mm. at the center, thus indicating 
that the instrument invaded the intracranial tissues and probably 
brought the trials of the victim to an end. 
In addition to these definite operations there are several significant 
scratches, apparently exploratory. The most conspicuous are three or 
four parallel cuts, the longest 25 mm. in length, extending upward and 
backward from a point 10 mm. beyond the postero-superior margin of 
the principal aperture, in a direction approximately parallel with the 
radial fracture removed in making this aperture (the principal scratch 
of this series appearing in plate Xxxv). Appearances indicate that 
these scratches originally extended farther downward and forward, and 
that their extremities were obliterated by the subsequent rasping. A 
single scratch extends almost directly backward from a point 15 mm. 
back of the main aperture for a distance of 6 or 7 mm., almost inter- 
secting the upper extremity of a rough groove extending downward 
17 mm., and crossing the posterior extremity of the principal rectilinear 
cut. Two rather conspicuous grooves appear downward and forward 
from the circular aperture; the more définite extends from the bridge 
below this aperture backward to the center of the main rectilinear 
incision. Along the suture below this incision there are conspicuous 
transverse scratches produced by scraping, rasping, or grinding with 
a rough edge or surface; and similar marks cross the curvilinear crack 
forward to the origin of the zygoma, where they unite with the striz 
connected with the main operation. The most remote traces of instru- 
mentation are two parallel cuts in the bone just below the temporo 
parietal suture, 10 mm. from its union with the lambdoid. (Only one 
of these marks appears in the reproduction.) 
The indications of sequence in the operation are somewhat indefinite, 
though it seems certain that the instrumentation succeeded, and was 
located by, the wound. It would appear that on dividing and pushing 
aside the scalp (after the manner indicated by cranium 16), the operator 
