60
J. N. BALL AND BRIDGET I. BAKER
V), and they contain neurosecretory material that stains with AF,
CAH, ATh, and AB (Palay, 1945; Stutinsky, 1953; Bargmann, 1953; Stahl
and Leray, 1962; Honma and Tamura, 196513). The majority of these
fibers probably terminate in the distal part of the neurohypophysial core
surrounded by the pars intermedia, ending in association with pituicytes
or blood vessels or with the pars intermedia cells. In addition, fibers with
these staining reactions have been observed closely associated with cells
of the pars distalis (Da Lage, 1958; Stahl and Leray, 1962; Sathyanesan,
1965a, 1966). In the eel, Olivereau (1967a) distinguished two kinds of
nearosecretory fibers with the light microscope; one type containing
classic neurosecretory material and mainly passing toward and penetrating the pars intermedia, the other type with material PAS + ve but AF -
ve, which penetrates the pars distalis. She tentatively equated these with
Type A and Type B fibers originating from the NPO and NLT (see
below, Section 11, C, 2). Similar distribution of the two kinds of fibers
can be seen in Poecilia (see chapter by Perks, this volume).
After hypophysectomy, classic neurosecretory material accumulates
along the course of the severed nerve axons in the infundibular area
(Stutinsky, 1953; Uemura et al., 1963; Sathyanesan, 1955a, 1966; Sathyanesan and Gorbman, 1965). Transection of the NPO-pituitary tracts in
Lepidogobiw also led to accumulation of AF + ve material proximal to
the cut, and eventually to loss of this material from the neurohypophysis
(Kobayashi et al., 1959). Thus the neurosecretory material is certainly
formed in the hypothalamus and transported to the pituitary along the
axons, as in other vertebrates (Pickford and Atz, 1957; Dodd and Kerr,
1963; Bern and Knowles, 1W). Exposure of hypophysectomized
Porichthys to continuous light induced movement of AF + ve material
from the NPO to the cut ends of the axons in the infundibulum (Sathyanesan, 1965a). The ends of the severed axons in hypophysectomized
goldfish and Poriclzthys regenerate so that the severed neurohypophysial
stalk eventually forms a kind of isolated neurohypophysial core with
axons terminating on blood vessels as in the normal condition (Sathyanesan and Gorbman, 1965; Sathyanesan, 1965a ) . In hypophysectomized
Clevelandia, the neurosecretory material that accumulated proximal to
the cut ends of the axons eventually disappeared, probably into blood
vessels that associated with the fibers ( Uemura et al., 1963).
The correspondence of this light microscope category with the Type
A fibers defined by ultrastructure is almost certain, though perhaps not
definitively established. Knowles (1965) defined Type A fibers as containing osmiophilic granules more than 100 mp in diameter, in contrast
to Type B fibers with smaller granules; and in Perca and Salmo Type A
fibers contain granules the same size as those in the cell bodies of the
J. N. BALL AND BRIDGET I. BAKER
V), and they contain neurosecretory material that stains with AF,
CAH, ATh, and AB (Palay, 1945; Stutinsky, 1953; Bargmann, 1953; Stahl
and Leray, 1962; Honma and Tamura, 196513). The majority of these
fibers probably terminate in the distal part of the neurohypophysial core
surrounded by the pars intermedia, ending in association with pituicytes
or blood vessels or with the pars intermedia cells. In addition, fibers with
these staining reactions have been observed closely associated with cells
of the pars distalis (Da Lage, 1958; Stahl and Leray, 1962; Sathyanesan,
1965a, 1966). In the eel, Olivereau (1967a) distinguished two kinds of
nearosecretory fibers with the light microscope; one type containing
classic neurosecretory material and mainly passing toward and penetrating the pars intermedia, the other type with material PAS + ve but AF -
ve, which penetrates the pars distalis. She tentatively equated these with
Type A and Type B fibers originating from the NPO and NLT (see
below, Section 11, C, 2). Similar distribution of the two kinds of fibers
can be seen in Poecilia (see chapter by Perks, this volume).
After hypophysectomy, classic neurosecretory material accumulates
along the course of the severed nerve axons in the infundibular area
(Stutinsky, 1953; Uemura et al., 1963; Sathyanesan, 1955a, 1966; Sathyanesan and Gorbman, 1965). Transection of the NPO-pituitary tracts in
Lepidogobiw also led to accumulation of AF + ve material proximal to
the cut, and eventually to loss of this material from the neurohypophysis
(Kobayashi et al., 1959). Thus the neurosecretory material is certainly
formed in the hypothalamus and transported to the pituitary along the
axons, as in other vertebrates (Pickford and Atz, 1957; Dodd and Kerr,
1963; Bern and Knowles, 1W). Exposure of hypophysectomized
Porichthys to continuous light induced movement of AF + ve material
from the NPO to the cut ends of the axons in the infundibulum (Sathyanesan, 1965a). The ends of the severed axons in hypophysectomized
goldfish and Poriclzthys regenerate so that the severed neurohypophysial
stalk eventually forms a kind of isolated neurohypophysial core with
axons terminating on blood vessels as in the normal condition (Sathyanesan and Gorbman, 1965; Sathyanesan, 1965a ) . In hypophysectomized
Clevelandia, the neurosecretory material that accumulated proximal to
the cut ends of the axons eventually disappeared, probably into blood
vessels that associated with the fibers ( Uemura et al., 1963).
The correspondence of this light microscope category with the Type
A fibers defined by ultrastructure is almost certain, though perhaps not
definitively established. Knowles (1965) defined Type A fibers as containing osmiophilic granules more than 100 mp in diameter, in contrast
to Type B fibers with smaller granules; and in Perca and Salmo Type A
fibers contain granules the same size as those in the cell bodies of the