MUNIZ—MC GEE] INSTRUMENTS WERE OF STONE 59 
the rather blunt tip expanded longitudinally in the form of a blade 
considerably broader than thick. The rectilinear incisions give little 
indication of the relative width and thickness of the tools, but the 
curvilinear kerfS suggest that the longitudinal width must have been 
two or three or more times the transverse dimension—i. e., that the tool 
must have been a blade measuring, at a distance of say 8 mm. from the 
tip, about 5 or 4 mm. from side to side, and somewhere between 5 and 
10 nm. from edge to edge. 
It is, of course, impossible to estimate, with any approach to accuracy, 
the length of the blade, which might or might not have been hafted, 
but it is practicable to estimate roughly the total length of the instru- 
ment, including the haft, if hafted, from the curvature in bottom pro- 
file of the incisions, assuming the tool to have been held in convenient 
fashion in onehand; and such an estimate, based on the well-preserved 
incisions in crania 1, 2, 14, 15, 16, and 17, ranges from about 50 or 75 to 
some 150 or 200 mm.; i. e., it seems probable that the instrument was 
long enough to be handled conveniently in one hand, with the occasional 
assistance of the other. 
Putting the various dimensions together, they are found to define a 
blade corresponding with an ordinary stone knife or spearhead, or with 
an arrowpoint attached to a short haft, while the dimensions are incon- 
sistent with those possessed by any known cutting instrument of metal. 
Considering next the longitudinal strie in the sides of the kerfs, it 
appears that they would naturally and necessarily be produced by the 
reciprocal operation of a knife or spearhead chipped from stone of 
coarse texture or of such structure as to give a splintery fracture, and 
that these features would not be produced by any known single-point 
tool of metal, polished stone, tooth, ov shell. Accordingly, the detailed 
features displayed by the collection afford practically conclusive evi- 
dence that the incising instrument was a stone blade of common form 
and character. There is absolutely no suggestion in any of the speci- 
mens that the kerfs were produced by any other kind of tool, either of 
other material than stone or of other form than a blunt single-tip blade. 
Several of the crania indicate that the rasping was effected by an 
irregularly rough surface, since the striz are unequal in depth and 
variable in contour and length. In only a single instance (cranium 8) 
are the strive sufficiently uniform even to suggest the use of a regularly 
formed rasp or file of metal or other tough material, and even in this case 
careful examination shows that the uniformity is almost certainly due 
to exceptional shortness of stroke in beveling the narrow marginal zone 
(1 to 9 mm. in width) of the outer table of the skull. In most cases the 
strive are precisely such as those traversing longitudinally the sides of 
the cuts, and this similarity suggests that they were effected simply by 
rubbing with the side of a blade chipped from stone of coarse texture 
or splintery fracture. 
