I think I may say that we found the hypothesis fit in with actual facts
in a sufficiently satisfactory manner. We found not a few matters, as,
for example, the sterility of hybrids, the principle underlying
longevity, the phenomena of old age, and puberty as generally near the
end of development, explain themselves with more completeness than I have
yet heard of their being explained on any other hypothesis. Most indeed
of these phenomena have been left hitherto without even an attempt at an
explanation.

We considered the most important difficulty in the way of instinct as
hereditary habit, namely, the structure and instincts of neuter insects;
these are very unlike those of their parents, and cannot, apparently, be
transmitted to offspring by individuals of the previous generation, in
whom such structure and instincts appeared, inasmuch as these creatures
are sterile. I do not say that the difficulty is wholly removed,
inasmuch as some obscurity must be admitted to remain as to the manner in
which the structure of the larva is aborted; this obscurity is likely to
remain till we know more of the early history of civilisation among bees
than I can find that we know at present; but I believe the difficulty was
reduced to such proportions as to make it little likely to be felt in
comparison with that of attributing instinct to any other cause than
inherited habit, or memory on the part of offspring, of habits contracted
in the persons of its ancestors. {127}

We then inquired what was the great principle underlying variation, and
answered, with Lamarck, that it must be "sense of need;" and though not
without being haunted by suspicion of a vicious circle, and also well
aware that we were not much nearer the origin of life than when we
started, we still concluded that here was the truest origin of species,
and hence of genera; and that the accumulation of variations, which in
time amounted to specific and generic differences, was due to
intelligence and memory on the part of the creature varying, rather than
to the operation of what Mr. Darwin has called "natural selection." At
the same time we admitted that the course of nature is very much as Mr.
Darwin has represented it, in this respect, in so far as that there is a
struggle for existence, and that the weaker must go to the wall. But we
denied that this part of the course of nature would lead to much, if any,
accumulation of variation, unless the variation was