Karl Friedrich von
Gärtner (1772–1850)
Gärtner was cited extensively by
Mendel (1865) for
the former's view that species varied only within
particular limits. Although interspecies
hybrids were possible, Gärtner thought
that they invariably reverted to type. According to Mendel, "Gärtner
by the results of [his] transformation experiments, was
led to oppose the opinion of those naturalists who dispute
the stability of plant species and believe in a
continuous evolution of plants. He perceives in the complete
transformation of one species into another an indubitable
proof that species are fixed within limits beyond
which they cannot change. Although this opinion cannot
be unconditionally accepted we find on the other hand
in Gärtner’s experiments a noteworthy confirmation of that
supposition regarding variability of cultivated plants which
has already been expressed."