t become more and more unworkable.

The only imaginable alternative is that the re-adjustments are effected
in course of time by natural selection. But, in the first place, as we
find no proof of concomitant variation among directly co-operative parts
which are closely united, there cannot be assumed any concomitant
variation among parts which are both indirectly co-operative and far
from one another. And, in the second place, before all the many
required re-adjustments could be made, the variety would die out from
defective constitution. Even were there no such difficulty, we should
still have to entertain a strange group of propositions, which would
stand as follows:--1. Change in one part entails, by reaction on the
organism, changes, in other parts, the functions of which are
necessarily changed. 2. Such changes worked in the individual, affect,
in some way, the reproductive elements: these being found to evolve
unusual structures when the constitutional balance has been continuously
disturbed. 3. But the changes in the reproductive elements thus caused,
are not such as represent these functionally-produced changes: the
modifications conveyed to offspring are irrelevant to these various
modifications functionally produced in the organs of the parents. 4.
Nevertheless, while the balance of functions cannot be re-established
through inheritance of the effects of disturbed functions on structures,
wrought throughout the individual organism; it can be re-established by
the inheritance of fortuitous variations which occur in all the affected
organs without reference to these changes of function.

Now without saying that acceptance of this group of propositions is
impossible, we may certainly say that it is not easy.

* * * * *

"But where are the direct proofs that inheritance of
functionally-produced modifications takes place?" is a question which
will be put by those who have committed themselves to the current
exclusive interpretation. "Grant that there are difficulties; still,
before the transmitted effects of use and disuse can be legitimately
assigned in explanation of them, we must have good evidence that the
effects of use and disuse _are_ transmitted."

Before dealing directly with this demurrer, let me deal with it
indirectly, by pointing out that the lack of recognized evidence may be
accounted for without assuming that there is not plenty of it.
Inattention and reluctant at