petition with forms
better fitted.

* * * * *

Secondly, there is a general consideration of the largest possible
significance in the present connexion--namely, that among all the
millions of structures and instincts which are so invariably, and for
the most part so wonderfully, adapted to the needs of the species
presenting them, we cannot find a single instance, either in the
vegetable or animal kingdom, of a structure or an instinct which is
developed for the exclusive benefit of another species. Now this great
and general fact is to my mind a fact of the most enormous, not to say
overwhelming, significance. The theory of natural selection has now been
before the world for more than thirty years, and during that time it had
stood a fire of criticism such as was never encountered by any
scientific theory before. From the first Darwin invited this criticism
to adduce any single instance, either in the vegetable or animal
kingdom, of a structure or an instinct which should unquestionably be
proved to be of exclusive use to any species other than the one
presenting it. He even went so far as to say that if any one such
instance could be shown he would surrender his whole theory on the
strength of it--so assured had he become, by his own prolonged
researches, that natural selection was the true agent in the production
of adaptive structures, and, as such, could never have permitted such a
structure to occur in one species for the benefit of another. Now, as
this invitation has been before the world for so many years, and has not
yet been answered by any naturalist, we may by this time be pretty
confident that it never will be answered. How tremendous, then, is the
significance of this fact in its testimony to Darwin's theory! The
number of animal and vegetable species, both living and extinct, is to
be reckoned by millions, and every one of these species presents on an
average hundreds of adaptive structures,--at least one of which in many,
possibly in most, if not actually in all cases, is peculiar to the
species that presents it. In other words, there are millions of adaptive
structures (not to speak of instincts) which are peculiar to the species
presenting them, and also many more which are the common property of
allied species: yet, notwithstanding this inconceivable profusion of
adaptive structures in organic nature, there is no single instance that
has been pointed out of the occurr