in one of the two breeds which are crossed, and latent or invisible in the
other breed; and in this case it is natural that the character which is
potentially present in both breeds should be prepotent. Thus, we have reason
to believe that there is a latent tendency in all horses to be dun-coloured
and striped; and when a horse of this kind is crossed with one of any other
colour, it is said that the offspring are almost sure to be striped. Sheep
have a similar latent tendency to become dark-coloured, and we have seen with
what prepotent force a ram with a few black spots, when crossed with white
sheep of various breeds, coloured its offspring. All pigeons have a latent
tendency to become slaty-blue, with certain characteristic marks, and it is
known that, when a bird thus coloured is crossed with one of any other colour,
it is most difficult afterwards to eradicate the blue tint. A nearly parallel
case is offered by those black bantams which, as they grow old, develop a
latent tendency to acquire red feathers. But there are exceptions to the rule:
hornless breeds of cattle possess a latent capacity to reproduce horns, yet
when crossed with horned breeds they do not invariably produce offspring
bearing horns.

We meet with analogous cases with plants. Striped flowers, though they can be
propagated truly by seed, have a latent tendency to become uniformly coloured,
but when once crossed by a uniformly coloured variety, they ever afterwards
fail to produce striped seedlings. (14/22. Verlot 'Des Varietes' 1865 page
66.) Another case is in some respects more curious: plants bearing peloric
flowers have so strong a latent tendency to reproduce their normally irregular
flowers, that this often occurs by buds when a plant is transplanted into
poorer or richer soil. (14/23. Moquin-Tandon 'Teratologie' page 191.) Now I
crossed the peloric snapdragon (Antirrhinum majus), described in the last
chapter, with pollen of the common form; and the latter, reciprocally, with
peloric pollen. I thus raised two great beds of seedlings, and not one was
peloric. Naudin (14/24. 'Nouvelles Archives du Museum' tome 1 page 137.)