he emotions
of the organic sense, to perform such and such acts.

"Hence the origin, in certain animals, of different complicated
actions, which has been called _industry_, and which are so
enthusiastically admired, because it has always been supposed, at
least tacitly, that these actions were contrived and deliberately
planned, which is plainly erroneous. They are evidently the fruit of
a necessity which has expanded and directed the habits of the
animals performing them, and which renders them such as we observe.

"What I have just said is especially applicable to the invertebrate
animals, in which there enters no act of intelligence. None of
these can indeed freely vary its actions; none of them has the power
of abandoning what we call its _industry_ to adopt any other kind.

"There is, then, nothing wonderful in the supposed industry of the
ant-lion (_Myrmeleon formica-leo_), which, having thrown up a
hillock of movable sand, waits until its booty is thrown down to the
bottom of its funnel by the showers of sand to become its victim;
also there is none in the manoeuvre of the oyster, which, to
satisfy all its wants, does nothing but open and close its shell. So
long as their organization is not changed they will always, both of
them, do what we see them do, and they will do it neither
voluntarily nor rationally.

"This is not the case with the vertebrate animals, and it is among
them, especially in the birds and mammals, that we observe in their
actions traces of a true _industry_; because in difficult cases
their intelligence, in spite of their propensity to habits, can aid
them in varying their actions. These acts, however, are not common,
and are only slightly manifested in certain races which have
exercised them more, as we have had frequent occasion to remark."

Lamarck then (chapter vi.) examines into the nature of the _will_, which
he says is really the principle underlying all the actions of animals.
The will, he says, is one of the results of thought, the result of a
reflux of a portion of the nervous fluid towards the parts which are to
act.

He compares the brain to a register on which are imprinted ideas of all
kinds acquired by the individual, so that this individual provokes at
will an effusion of the nervous fluid on this register, and directs it
to any particular page. The remainder of the second volume
(chapter vii.) is devoted to the un