g in the most ancient; and this
character increases, by degrees, in the works of the Roman period." Godron
also has remarked that "the pigs of the ancient Egyptians had not their
ears enlarged and pendent."[746] But it is remarkable that the drooping of
the ears, though probably the effect of disuse, is not accompanied by any
decrease in size; on the contrary, when we remember that animals so
different as fancy rabbits, certain Indian breeds of the goat, our petted
spaniels, bloodhounds, and other dogs, have enormously elongated ears, it
would appear as if disuse actually caused an increase in length. With
rabbits, the drooping of the much elongated ears has affected even the
structure of the skull.

The tail of no wild animal, as remarked to me by Mr. Blyth, is curled;
whereas pigs and some races of dogs have their tails much curled. This
deformity, therefore, appears to be the result of domestication, but
whether in any way connected with the lessened use of the tail is doubtful.

{302}

The epidermis on our hands is easily thickened, as every one knows, by hard
work. In a district of Ceylon the sheep have "horny callosities that defend
their knees, and which arise from their habit of kneeling down to crop the
short herbage, and this distinguishes the Jaffna flocks from those of other
portions of the island;" but it is not stated whether this peculiarity is
inherited.[747]

The mucous membrane which lines the stomach is continuous with the external
skin of the body; therefore it is not surprising that its texture should be
affected by the nature of the food consumed, but other and more interesting
changes likewise follow. Hunter long ago observed that the muscular coat of
the stomach of a gull (_Larus tridactylus_) which had been fed for a year
chiefly on grain was thickened; and, according to Dr. Edmondston, a similar
change periodically occurs in the Shetland Islands in the stomach of the
_Larus argentatus_, which in the spring frequents the corn-fields and feeds
on the seed. The same careful observer has noticed a great change in the
stomach of a raven which had been long fed on vegetable food. In the case
of an owl (_Strix grallaria_) similarly treated, Menetries states that the
form of the stomach was changed, the inner coat became leathery, and the
liver increased in size. Whether these modifications in the digestive
organs would in the course of generations become inherited is not
known.[748]

The increase