See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1869
1872

degrees and kinds of resemblance 1866 1869 1872
resemblance 1859 1860 1861

With 1859 1860 1861 1866 1869
So I believe it to be with varieties of plants; and with 1872

parent-form, 1859 1860 1866 1869 1872
parent form, by 1861

and he experimented on uncultivated species of willows; whilst Naudin, on the other hand, insists in the strongest terms on the almost universal tendency to reversion in hybrids, and he experimented chiefly on cultivated plants. Gärtner further
insists
states
that when any two species, although most closely allied to each other, are crossed with a third species, the hybrids are widely different from each other;
whereas
whereas,
if two very distinct varieties of one species are crossed with another species, the hybrids do not differ much. But this conclusion, as far as I can make out, is founded on a single experiment; and seems directly opposed to the results of several experiments made by Kölreuter.
These
Such
alone are the unimportant
differences,
differences
which Gärtner is able to point
out,
out
between hybrid and mongrel plants. On the other hand, the degrees and kinds of resemblance in mongrels and in hybrids to their respective parents, more especially in hybrids produced from nearly related species,
follows
follow
according to Gärtner the same laws. When two species are crossed, one has sometimes a prepotent power of impressing its likeness on the
hybrid.
hybrid;
and
and
so
so
I
I
believe
believe
it
it
to
to
be
be
with
with
varieties
varieties
of
of
plants.
plants.
With animals one variety certainly often has this prepotent power over another variety. Hybrid plants produced from a reciprocal cross, generally resemble each other closely; and so it is with
mongrel
mongrels
plants from
from
a reciprocal cross. Both hybrids and mongrels can be reduced to either pure parent-form,
by
by
repeated crosses in successive generations with either parent.
These several remarks are apparently applicable to animals; but the subject is here
excessively
much
complicated, partly owing to the existence of secondary sexual characters; but more especially owing to prepotency in transmitting likeness running more strongly in one