Another general consideration which has had great influence on my mind is,
that with all hermaphrodite animals and plants, which it might have been
thought would have perpetually fertilised themselves and been thus subjected
for long ages to the closest interbreeding, there is not a single species, as
far as I can discover, in which the structure ensures self-fertilisation. On
the contrary, there are in a multitude of cases, as briefly stated in the
fifteenth chapter, manifest adaptations which favour or inevitably lead to an
occasional cross between one hermaphrodite and another of the same species;
and these adaptive structures are utterly purposeless, as far as we can see,
for any other end.

[With CATTLE there can be no doubt that extremely close interbreeding may be
long carried on advantageously with respect to external characters, and with
no manifest evil as far as constitution is concerned. The case of Bakewell's
Longhorns, which were closely interbred for a long period, has often been
quoted; yet Youatt says (17/4. 'Cattle' page 199.) the breed "had acquired a
delicacy of constitution inconsistent with common management," and "the
propagation of the species was not always certain." But the Shorthorns offer
the most striking case of close interbreeding; for instance, the famous bull
Favourite (who was himself the offspring of a half-brother and sister from
Foljambe) was matched with his own daughter, granddaughter, and great-
granddaughter; so that the produce of this last union, or the great-great-
granddaughter, had 15-16ths, or 93.75 per cent of the blood of Favourite in
her veins. This cow was matched with the bull Wellington, having 62.5 per cent
of Favourite blood in his veins, and produced Clarissa; Clarissa was matched
with the bull Lancaster, having 68.75 of the same blood, and she yielded
valuable offspring. (17/5. I give this on the authority of Nathusius 'Ueber
Shorthorn Rindvieh' 1857 s. 71, see also 'Gardeners Chronicle' 1860 page 270.
But Mr. J. Storer, a large breeder of cattle, informs me that the parentage of