See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1866
1872

The sterility of these 1869 1872
These 1866

when 1869 1872
which are so sterile, although 1866

that of hybrids 1869 1872
hybrids 1866

se. 1869
se, and we all know how sterile these latter generally are. 1866
se . 1872

may be called, are not fully fertile. It is possible to raise
form
from
dimorphic species, both long-styled and short-styled illegitimate plants, and from trimorphic plants all three illegitimate
forms.
forms;
so that
....
These
these
can
be
then be
properly united in a legitimate manner. When this is done, there is no apparent reason why they should not yield as many seeds as did their parents when legitimately fertilised. But such is not the
case.
case;
They
they
are all infertile,
but
but
in various degrees; some being so utterly and incurably sterile that they did not yield during four seasons a single seed or even
a
....
seed-capsule. The sterility of these illegitimate plants, when united with each other in a legitimate manner, may be strictly compared with that of hybrids when crossed inter se.
If,
When
on the other
hand,
hand
a hybrid is crossed with either pure parent-species, the sterility is usually much
lessened;
lessened:
and so it is when an illegitimate plant is fertilised by a legitimate plant. In the same manner as the sterility of hybrids does not always run parallel with the difficulty of making the first cross between
its
the
two parent-species, so the sterility of certain illegitimate plants was unusually great, whilst the sterility of the union from which they were derived was by no means great. With hybrids raised from the same seed-capsule the degree of sterility is innately variable, so it is in a marked manner with illegitimate plants. Lastly, many hybrids are profuse and persistent flowerers, whilst other and more sterile hybrids produce few flowers, and are weak, miserable dwarfs; exactly similar cases occur with the illegitimate offspring of various dimorphic and trimorphic plants.
Altogether there is the closest identity in character and behaviour between illegitimate plants and hybrids. It is hardly an exaggeration to maintain that
illegitimate plants
the former
are hybrids,
but
but
produced within the limits