intelligible. In what manner characters may be conceived to lie latent, will
be considered in a future chapter to which I have lately alluded.

LATENT CHARACTERS.

But I must explain what is meant by characters lying latent. The most obvious
illustration is afforded by secondary sexual characters. In every female all
the secondary male characters, and in every male all the secondary female
characters, apparently exist in a latent state, ready to be evolved under
certain conditions. It is well known that a large number of female birds, such
as fowls, various pheasants, partridges, peahens, ducks, etc., when old or
diseased, or when operated on, assume many or all of the secondary male
characters of their species. In the case of the hen-pheasant this has been
observed to occur far more frequently during certain years than during others.
(13/54. Yarrell 'Phil. Transact.' 1827 page 268; Dr. Hamilton in 'Proc.
Zoolog. Soc.' 1862 page 23.) A duck ten years old has been known to assume
both the perfect winter and summer plumage of the drake. (13/55. 'Archiv.
Skand. Beitrage zur Naturgesch.' 8 s. 397-413.) Waterton (13/56. In his
'Essays on Nat. Hist.' 1838 Mr. Hewitt gives analogous cases with hen-
pheasants in 'Journal of Horticulture' July 12, 1864 page 37. Isidore Geoffroy
Saint-Hilaire in his 'Essais de Zoolog. Gen.' ('Suites a Buffon' 1842 pages
496-513), has collected such cases in ten different kinds of birds. It appears
that Aristotle was well aware of the change in mental disposition in old hens.
The case of the female deer acquiring horns is given at page 513.) gives a
curious case of a hen which had ceased laying, and had assumed the plumage,
voice, spurs, and warlike disposition of the cock; when opposed to an enemy
she would erect her hackles and show fight. Thus every character, even to the
instinct and manner of fighting, must have lain dormant in this hen as long as
her ovaria continued to act. The females of two kinds of deer, when old, have
been known to acquire horns; and, as Hunter has remarked, we see something of