_
THE MENTAL LIFE OF FISHES
'
331
_
feed, but behind these phenomena is a more general instinct
…
which _we cannot fail to recognise. Perhaps the best
example is that of the little Sticklebacks, especially the
freshwater forms.
In the summer they come into the
shallow water and play about in the
In the
autumn and winter they retire into deeper water, and roam
*
about in large companies ; solitary individuals are seldom
met with.
The same 'is true of the marine shes, and it
would almost seem, in Some cases, as if they recogniseda
_
leader Or posted sentinels.
:
_
Instinctive or subconscious actions may be
two elements, the reaction of the whole organism to an
external stimulus and “the reaCtion of a part only. = The
former are generally known as tr0pisms, the latter as reex
actions. ,Thesegràde into one another, but on the whole
can be readin distinguished.
.
'
-
The tropisms c0nstitute the most important part of the
activities of
and plants, from the lowest to the
highest. ,— « In the simplest= forms of life, unicellular organir‘sms,
directed, activity
'
is} apparent 111
,_
of, diverse
_
stimuli.
towards light,: for? example, others
—
away from
energy, gravity, and chemical
composition _Lo£ the
lead _;to similar reactions.
_
W1th1n the cell itself it would:seem-_that movement: comes
'
differences in the protoplasm (Pantin, 1923),
partly chemical and partly physical‘in their nature, which
are connected with, though not. altogether determined by,
the varying stimuli. In the digestion of food and the
movements of leucocytes in general the many-celled animals,
including shes and man, are absolutely dependent on these
instinctive activities of simple cells.
_
.
;…
It is not only the single cells, however, that display
tr0pism ; the, whole body of a,highly specialisedorgæisin
may act-as one piece in, the same way.
know°how
insects and birds are attràcted to a light in the darkness.
'
Many animals, like the Earthworms, remainin their burrows
_
byday and 5creep abrdad. at night ; they resp0nd,to a certain
intensity of light—waves. Sinlarly, the, Eels migrate by
THE MENTAL LIFE OF FISHES
'
331
_
feed, but behind these phenomena is a more general instinct
…
which _we cannot fail to recognise. Perhaps the best
example is that of the little Sticklebacks, especially the
freshwater forms.
In the summer they come into the
shallow water and play about in the
In the
autumn and winter they retire into deeper water, and roam
*
about in large companies ; solitary individuals are seldom
met with.
The same 'is true of the marine shes, and it
would almost seem, in Some cases, as if they recogniseda
_
leader Or posted sentinels.
:
_
Instinctive or subconscious actions may be
two elements, the reaction of the whole organism to an
external stimulus and “the reaCtion of a part only. = The
former are generally known as tr0pisms, the latter as reex
actions. ,Thesegràde into one another, but on the whole
can be readin distinguished.
.
'
-
The tropisms c0nstitute the most important part of the
activities of
and plants, from the lowest to the
highest. ,— « In the simplest= forms of life, unicellular organir‘sms,
directed, activity
'
is} apparent 111
,_
of, diverse
_
stimuli.
towards light,: for? example, others
—
away from
energy, gravity, and chemical
composition _Lo£ the
lead _;to similar reactions.
_
W1th1n the cell itself it would:seem-_that movement: comes
'
differences in the protoplasm (Pantin, 1923),
partly chemical and partly physical‘in their nature, which
are connected with, though not. altogether determined by,
the varying stimuli. In the digestion of food and the
movements of leucocytes in general the many-celled animals,
including shes and man, are absolutely dependent on these
instinctive activities of simple cells.
_
.
;…
It is not only the single cells, however, that display
tr0pism ; the, whole body of a,highly specialisedorgæisin
may act-as one piece in, the same way.
know°how
insects and birds are attràcted to a light in the darkness.
'
Many animals, like the Earthworms, remainin their burrows
_
byday and 5creep abrdad. at night ; they resp0nd,to a certain
intensity of light—waves. Sinlarly, the, Eels migrate by