diencephalon.
Olfactory impulses are conveyed to the
commissure is also notable.
The olfactory impulses from
diencephalon by these two large ber bundles and tractus
the habenulae are conveyed to the nucleus interpeduncularis
olfacto-habenularis which corresponds to the stria medullaris
of the mesencephalon.
thalami of higher animals.
However, it is certain that in the
ln many sh, characteristic nerve structure situated in the
telencephalon of sh the ascending bers are not numerous.
ventral thalamus and extended to the hypothalamus is to
Nervus terminalis as observed in higher animals including
be observed.
This was found by Fritsch (1878) and is
man
is also found in sh.
It is a sensory function and is a
called nucleus rotundus.
Various names are given to it by
slender ber bundle reaching the olfactory lobe
different scholars.
ln addition to large ovoidal nucleus
accompanied by the tractus olfactorlus, and then further
rotundus proper, there are to be observed on the lateral and
proceeding to the hypothalamus.
Its exact function is still
the medial of the said nucleus, nucleus subrotundus and
not determined.
nucleus prerotundus which are thought to be related to the
The telencephalon of almost all the sh, le, the lobus
said nucleus.
Nucleus rotundus greatly diers in size and
olfactorius, is divided into right and left hemispheres by the
structure according to the kind of sh.
But generally, the
ventriculus medius telencephali.
However, in some species
outer border of this nucleus is surrounded by a medullated
such as Pleuronectidae and Bothidae, it is asymmetrical
capsula and consists of small cells.
Large glommerular
(*Lz‘manda herzenstez‘m‘, *Pa7»aliclzthys 0livaceus).
cells are clustered inside.
As these cells are penetrated by
Generally, this ventriculus is extended to the anterior
the commissure horizontalis, which is thought to have
commissure forming two lobi of right and left, but in
relation to sight, and as they receive olfactory impulses as
certain sh (*Channa argus), this groove is shallow and
well as those of gustation probably through the tertiary
therefore, lobi of both sides closely adhere to each other,
gustatory tract, they would seem to be the centers related
forming a septal region.
to feeding.
The hypothalamus of the sh is strikingly developed as
The diencephalon of sh can be divided into the
compared with other parts of the brain.
The hypothalamus
epithalamus, the thalamus and the hypothalamus, but it
starts from the ventro-posterior of the forebrain.
There is
differs greatly from that of mammals.
to be observed on both sides of the preoptic recessus, the
The hypothalamic region is connected With the belly side Of
nucleus preopticus which corresponds to the paraventricular
the anterior commissure region Of the forebrain and
nucleus of mammals.
The nucleus preopticus magnocellularls
extended ventrally towards the hYPOPhYSÎSThe |0bUS
consisting of large cells is clearly distinguished from the
inferior, a part Of the
WhÎCh ÎS well-developed
nucleus preopticus parvocellularis which consists of small
in 5h7
expanded on b0th 5Ïd95cells.
This nucleus receives olfactory impulses from the
The thalamus region in 5h iS not well-developed.
in many
forebrain through the medial forebrain bundle, and from
sh, nucleus geniculatum latelaris is placed in such a position
here nerve bers are sent to the hypophysis and the
as to be buried in the tractus OPÎÎCUSThere iS nothing to
saccus vasculosus.
A very interesting feature is that in
be observed in 5h that corresponds ”EO the nucleus
sh, the neuron of nucleus preopticus magnocellularis
geniculatum medialis Of higher animals.
The HUCÎGUS
consists of neuro-secretory cells (Scharrer, 1928), as
habenulae which constitutes the greater part of the
previously stated (p. 5)_
passing through the axon of
epithalamus is situated on the dorsal part of the thalamus.
this neuron, hormone is conveyed to the hypophysis.
This
in some 5h’ the nucleus habenulae diers in size between
nucleus is particularly well-developed in *Regalecus russellz‘z‘
the right and left (*Ha7'engul“
*Smmbemmoms nz‘phom‘us).
and *L0phius lituZon.
Lobus inferior is a structure
BUÎ generally speaking, the nucleus habenulae is
extensively at the bottom of the brain.
Lateral
well-developed in Sh With well-developed olfactory lobe,
and medial forebrain bundles terminate widely here and the
and it is connected With the olfactory centers Of the
gustatory impulses are conveyed to this region by tertiary
telencephalon by the olfacto-habenular tract.
Habenular
gustatory bers.
Moreover, bers from the optio tectum and
8—9
Olfactory impulses are conveyed to the
commissure is also notable.
The olfactory impulses from
diencephalon by these two large ber bundles and tractus
the habenulae are conveyed to the nucleus interpeduncularis
olfacto-habenularis which corresponds to the stria medullaris
of the mesencephalon.
thalami of higher animals.
However, it is certain that in the
ln many sh, characteristic nerve structure situated in the
telencephalon of sh the ascending bers are not numerous.
ventral thalamus and extended to the hypothalamus is to
Nervus terminalis as observed in higher animals including
be observed.
This was found by Fritsch (1878) and is
man
is also found in sh.
It is a sensory function and is a
called nucleus rotundus.
Various names are given to it by
slender ber bundle reaching the olfactory lobe
different scholars.
ln addition to large ovoidal nucleus
accompanied by the tractus olfactorlus, and then further
rotundus proper, there are to be observed on the lateral and
proceeding to the hypothalamus.
Its exact function is still
the medial of the said nucleus, nucleus subrotundus and
not determined.
nucleus prerotundus which are thought to be related to the
The telencephalon of almost all the sh, le, the lobus
said nucleus.
Nucleus rotundus greatly diers in size and
olfactorius, is divided into right and left hemispheres by the
structure according to the kind of sh.
But generally, the
ventriculus medius telencephali.
However, in some species
outer border of this nucleus is surrounded by a medullated
such as Pleuronectidae and Bothidae, it is asymmetrical
capsula and consists of small cells.
Large glommerular
(*Lz‘manda herzenstez‘m‘, *Pa7»aliclzthys 0livaceus).
cells are clustered inside.
As these cells are penetrated by
Generally, this ventriculus is extended to the anterior
the commissure horizontalis, which is thought to have
commissure forming two lobi of right and left, but in
relation to sight, and as they receive olfactory impulses as
certain sh (*Channa argus), this groove is shallow and
well as those of gustation probably through the tertiary
therefore, lobi of both sides closely adhere to each other,
gustatory tract, they would seem to be the centers related
forming a septal region.
to feeding.
The hypothalamus of the sh is strikingly developed as
The diencephalon of sh can be divided into the
compared with other parts of the brain.
The hypothalamus
epithalamus, the thalamus and the hypothalamus, but it
starts from the ventro-posterior of the forebrain.
There is
differs greatly from that of mammals.
to be observed on both sides of the preoptic recessus, the
The hypothalamic region is connected With the belly side Of
nucleus preopticus which corresponds to the paraventricular
the anterior commissure region Of the forebrain and
nucleus of mammals.
The nucleus preopticus magnocellularls
extended ventrally towards the hYPOPhYSÎSThe |0bUS
consisting of large cells is clearly distinguished from the
inferior, a part Of the
WhÎCh ÎS well-developed
nucleus preopticus parvocellularis which consists of small
in 5h7
expanded on b0th 5Ïd95cells.
This nucleus receives olfactory impulses from the
The thalamus region in 5h iS not well-developed.
in many
forebrain through the medial forebrain bundle, and from
sh, nucleus geniculatum latelaris is placed in such a position
here nerve bers are sent to the hypophysis and the
as to be buried in the tractus OPÎÎCUSThere iS nothing to
saccus vasculosus.
A very interesting feature is that in
be observed in 5h that corresponds ”EO the nucleus
sh, the neuron of nucleus preopticus magnocellularis
geniculatum medialis Of higher animals.
The HUCÎGUS
consists of neuro-secretory cells (Scharrer, 1928), as
habenulae which constitutes the greater part of the
previously stated (p. 5)_
passing through the axon of
epithalamus is situated on the dorsal part of the thalamus.
this neuron, hormone is conveyed to the hypophysis.
This
in some 5h’ the nucleus habenulae diers in size between
nucleus is particularly well-developed in *Regalecus russellz‘z‘
the right and left (*Ha7'engul“
*Smmbemmoms nz‘phom‘us).
and *L0phius lituZon.
Lobus inferior is a structure
BUÎ generally speaking, the nucleus habenulae is
extensively at the bottom of the brain.
Lateral
well-developed in Sh With well-developed olfactory lobe,
and medial forebrain bundles terminate widely here and the
and it is connected With the olfactory centers Of the
gustatory impulses are conveyed to this region by tertiary
telencephalon by the olfacto-habenular tract.
Habenular
gustatory bers.
Moreover, bers from the optio tectum and
8—9