CRANIOLOGICAL DIFFERENCES BETWEEN THE ASS AND THE HORSE. 409 
jossa of the lower jaw. The angle formed by the two lines is the positive or negative 
parvetal-crest-curvature index (Scheitelkruemmungsindex); the angle being positive 
(+) when the crista lies below the Lesbre line, and negative (— ) when the crista 
lies above the Lesbre line. According to this, horses should almost always have 
a negative, and asses a positive index. 
Since the ‘‘Lesbre line’’ leaves at times something to be wished for, I have 
chosen a second-control index which expresses the size of the acute angle formed 
between the prolongation of the facial tangent and that of a tangent on the brain 
part of the frontal and of the parietalia. In the ass this angle is about 40°, and 
in the horse 20° to 30°. 
As regards the bones of the facies, it is to be noted that the observations 
of the length of the free part of the nasal bones have absolutely no value, since 
this is wholly individual, or possibly also subject to racial variations. Also I 
do not find the shape of the sutures of the nasalia with the frontal and the lacrimal 
to be always characteristic; if they are useful, as stated by Salenski and Tscherski, 
they are too dependent on the width of the frontal to be decisive. Not more so 
is the shape of the lacrimal on which Riitimeyer seemed to place great reliance; 
nor can the triangular form of the orbital be used as a characteristic of species. 
Lastly, as regards the teeth characteristics, the occurrence of the ‘‘spur’’ 
must be used, notwithstanding Lesbre’s assurances, with some caution; I agree 
with Rttimeyer, Tscherski, and Owen, when IJ assign a higher value to the position 
of the internal lobule and its form, as also to the size of premolar 2 and molar 3. 
In this connection I have made some very instructive experiments by grinding 
on teeth of asses and horses, and have thereby arrived at the conviction that, 
as regards the ‘“‘spur,”’ by grinding to a sufficient depth, one may make out of every 
horse tooth an ass tooth, and sometimes from an ass tooth a horse tooth, without 
taking into account that in the first teeth of the ass ever published (Owen, plate 
Lvul, fig. 1) the spur shows on all the teeth and even double on one. Such cases 
are, however, extremely rare, and the ‘‘spur’’ is nevertheless to be regarded 
as a useful characteristic. 
After this review of the criteria in question we can pass now to a comparison 
of the ancient Egyptian mummified ass with the horse of Auvernier. The brain- 
skull of the ass of Abadieh shows the following relations: the ear-load index 
(Ohrbelastungsindex) is 42° with the foramen tangent, 35° with the condylus 
tangent; the same index on the skull of the Auvernier horse is 28° with the foramen 
tangent (B1); the condylus tangent (B2) is not measurable, as the condyli are 
broken off. The parietal curvature index (Scheitelkruemmungsindex) is + 22° 
on the ass of Abadieh, and —7° on the horse of Auvernier. Riitimeyer remarked 
that there was something asslike in the shortness of head and width of forehead 
of the equid of Auvernier. 
Teeth.—I have already discussed the teeth characteristics as described by 
Riitimeyer, and have repeatedly drawn the conclusion that the equid of Auvernier 
is a horse. The teeth are indeed very short and close-set. But we see clearly 
the horselike shape of the internal lobule which is very widely drawn out in two 
horns, while in the ass of Abadieh it is round and placed median. Then, too, 
