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244 THE WILL IN NATURE.
their being occasioned by stimuli or by motives, i.e. in their
having a brain for their medium or not ;
and the stimulus
may again be merely interior or exterior. In several
animals of a higher order crustaceans and even fishes
he finds that the voluntary and vital movements, for in
stance locomotion and respiration, entirely coincide: a
clear proof that their origin and essence are identical.
He says p. 188 : In the family of the actinia, star
fishes, sea-urchins, and holothurice (echinodermata pedata
Cuv.), it is evident that the movement of the fluids de
pends upon the will of the animals and that it is a
means of locomotion." Then again p. 288: "The gullet
of mammals has at its upper end the pharynx, which
expands and contracts by means of muscles resembling
voluntary muscles in their formation, yet which do not
obey the will." Here we see how the limits of the move
ments proceeding from the will and of those assumed
to be foreign to it, merge into one another. Ibid., p. 293 :
"Thus movements having all the appearance of being
voluntary, take place in the stomachs of ruminants. They
do not however always stand in connection with the rumi
nating process only. Even the simpler human stomach
and that of many animals only allows free passage to what
is digestible through its lower orifice, and rejects what is
indigestible by vomiting."
There is moreover special evidence that the movements
induced by stimuli (involuntary movements) proceed from
the will just as well as those occasioned by motives
(voluntary movements) : for instance, when the same
movement follows now upon a stimulus, now again
upon a motive, as is the case when the pupil of the
eye is contracted. This movement, when caused by in
creased light, follows upon a stimulus; whereas, when
occasioned by the wish to examine a very small object
be-
minutely in close proximity, it follows upon a motive ;