in the full-grown state would be explained. Before
practically{469} endeavouring to discover in our domestic races whether
the structure or form of the young has or has not changed in an exactly
corresponding degree with the changes of full-grown animals, it will be
well to show that it is at least quite _possible_ for the primary
germinal vesicle to be impressed with a tendency to produce some change
on the growing tissues which will not be fully effected till the animal
is advanced in life.

{467} This corresponds to the _Origin_, Ed. i. pp. 443-4, vi. p.
610: the "feline animal" is not used to illustrate the
generalisation, but is so used in the Essay of 1842, p. 42.

{468} _Origin_, Ed. i. p. 447, vi. p. 613.

{469} In the margin is written "Get young pigeons"; this was
afterwards done, and the results are given in the _Origin_, Ed. i.
p. 445, vi. p. 612.

From the following peculiarities of structure being inheritable and
appearing only when the animal is full-grown--namely, general size,
tallness (not consequent on the tallness of the infant), fatness either
over the whole body, or local; change of colour in hair and its loss;
deposition of bony matter on the legs of horses; blindness and deafness,
that is changes of structure in the eye and ear; gout and consequent
deposition of chalk-stones; and many other diseases{470}, as of the
heart and brain, &c., &c.; from all such tendencies being I repeat
inheritable, we clearly see that the germinal vesicle is impressed with
some power which is wonderfully preserved during the production of
infinitely numerous cells in the ever changing tissues, till the part
ultimately to be affected is formed and the time of life arrived at. We
see this clearly when we select cattle with any peculiarity of their
horns, or poultry with any peculiarity of their second plumage, for such
peculiarities cannot of course reappear till the animal is mature.
Hence, it is certainly _possible_ that the germinal vesicle may be
impressed with a tendency to produce a long-limbed animal, the full
proportional length of whose limbs shall appear only when the animal is
mature{471}.

{470} In the _Origin_, Ed. i. the corresponding passages are at pp.
8, 13, 443, vi. pp. 8, 15, 610. In the _Origin_, Ed. i. I have not
found a passage so striking as that which occurs a few lines lower
"that the germinal vesicle is impressed with some power which