ale reproductive elements having been
affected prior to the act of conception. Several reasons make me believe
in this; but the chief one is the remarkable effect which confinement or
cultivation has on the functions of the reproductive system; this
system appearing to be far more susceptible than any other part of the
organisation, to the action of any change in the conditions of life.
Nothing is more easy than to tame an animal, and few things more
difficult than to get it to breed freely under confinement, even in the
many cases when the male and female unite. How many animals there
are which will not breed, though living long under not very close
confinement in their native country! This is generally attributed to
vitiated instincts; but how many cultivated plants display the utmost
vigour, and yet rarely or never seed! In some few such cases it has
been found out that very trifling changes, such as a little more or less
water at some particular period of growth, will determine whether or not
the plant sets a seed. I cannot here enter on the copious details which
I have collected on this curious subject; but to show how singular the
laws are which determine the reproduction of animals under confinement,
I may just mention that carnivorous animals, even from the tropics,
breed in this country pretty freely under confinement, with the
exception of the plantigrades or bear family; whereas, carnivorous
birds, with the rarest exceptions, hardly ever lay fertile eggs. Many
exotic plants have pollen utterly worthless, in the same exact
condition as in the most sterile hybrids. When, on the one hand, we
see domesticated animals and plants, though often weak and sickly, yet
breeding quite freely under confinement; and when, on the other hand,
we see individuals, though taken young from a state of nature,
perfectly tamed, long-lived, and healthy (of which I could give numerous
instances), yet having their reproductive system so seriously affected
by unperceived causes as to fail in acting, we need not be surprised
at this system, when it does act under confinement, acting not quite
regularly, and producing offspring not perfectly like their parents or
variable.

Sterility has been said to be the bane of horticulture; but on this
view we owe variability to the same cause which produces sterility; and
variability is the source of all the choicest productions of the garden.
I may add, that as some organisms will breed most freel