Proceedings of the Linnean Society of London - University Library

LIIfNEAK SOCIETY OF LONDON. 49
great-great-grandson of " Darley Arabian,"' a horse purchased at
Aleppo and shipped to England in 1 705.
The anthor drew attention to a passage in Darwin's ' Yariation
ot" Animals and Plants under Domestication ' (ed. 2, vol. i. p. 52),
to the effect that "in various countries horn-like projections
have been observed on the frontal bones of the horse : in one
case described by Mr. Percival they arose about 2 inches above
the orbital processes, and were ' very like those in a calf from
five to six mouths' old,' being from half to three-quarters of an
inch in length. Azara has described two cases in South America,
in which the projections were between 3 or 4 inches in length
other instances have occurred in Spain."' " The French translator
of Azara refers to other cases mentioned by Huzard as having
occurred in Spain."
Dr. Eustace considers that, although both of the two horses
that formed the subject of his paper were of a delicate consti-
tution, and Lord Rivers's horse died when only four years' old,
the prominences cannot be looked upon as exostoses due to disease.
He considers the cases to be true instances of " reversion," the
reappearance in a rudimentary condition of structures which once
existed in a functionally perfect condition. Dr. Eustace is consequently
led to question the accuracy of the view held by the
late Mr. Romanes and others that true bilateral horns are peculiar
to, and an evidence of later specialization among the Ruminants ;
and he regards it as pi'obable that the possession of horns was a
feature of the ancestral stock of the Ungulates prior to the
differentiation of the Ruminants and the non-Ruminants.
LINN. see. PROCEEDINGS,— SESSION 1902-1903.
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