18
J. N. BALL AND BRIDGET I. BAKER
above), and in addition these workers observed with phase contrast the
emission of granules from the constantly rippling and undulating membrane of the living cell. Sage ( 1968), working with X i p h o p h o w glands,
used elaborate techniques to show that the 7 cells lost material in uitro,
and that this loss was greater on more dilute media than on a medium
with approximately the same sodium content as the fish serum. He did
not specifically determine whether dilution of the medium increased the
synthetic rate of the cells, in addition to enhancing their rate of discharge
(although this is implied by their degranulation in the presence of
cyanide) ; certainly, in P. ktipinna transferred to freshwater from dilute
seawater, plasma sodium falls through the range of concentrations employed by Sage concomitantly with the onset of increased discharge and
synthesis in the prolactin cells ( Ball, 1967, 19eQ).
2. ACTH CELLS (CORTICOTROPS, L CELLS, OR X CELLS)
The ACTH cells, characteristically disposed in a sheet at the interface
between the rostra1 pars distalis and the neurohypophysis (Figs. 1 and
2), have been recognized morphologically in teleosts for many years (see,
e.g., Bock, 1928; Kerr, 1942a,b; Vervoort, 1957), but their significance
was not known. Some workers thought that they were aberrant or immature forms of the 9 cells (Bock, 1928; Vervoort, 1957; cf. Follenius,
1963a), while Bugnon ( 1960a,b) suggested they might represent the pars
tuberalis of higher vertebrates (cf. Wingstrand, 1966a). In recognition of
their enigmatic nature, Olivereau (1963b) termed them the “X cells.”
In Poecilia, the L cells are usually truly chromophobic (that is, without granules that can be stained by any of the standard dyes or histochemical techniques ) ; but sometimes they display a very fine, powderlike
granulation, faintly staining with erythrosin in Cleveland Wolfe or A& B
preparations, or with azocarmine in the Azan technique. They may also
stain a faint purple after Aliz B or gray with lead hematoxylin ( PbH).
They are elongated cells, usually arranged with the long axis perpendicular to the adeno-neurohypophysial interface. The cells are small, and the
absence of distinct granulation makes it difEcult to discern the cell outlines. The most characteristic feature in this species is the elongated
nucleus with a distinctive scattering of chromatin which gives the nucleus
an easily recognizable spotted appearance. The nucleolus in most normal
cells is insignificant or undetectable (Figs. 3 and 12; see also Fig. 13).
In the eel (Fig. 14) the L cells are much better granulated than in
Poecilia, and the granulation stains weakly with erythrosin and quite
strongly with Alizarin blue. The granulation is also strongly stained by
PbH which picks out the cells easily, although it is not a specific stain for
J. N. BALL AND BRIDGET I. BAKER
above), and in addition these workers observed with phase contrast the
emission of granules from the constantly rippling and undulating membrane of the living cell. Sage ( 1968), working with X i p h o p h o w glands,
used elaborate techniques to show that the 7 cells lost material in uitro,
and that this loss was greater on more dilute media than on a medium
with approximately the same sodium content as the fish serum. He did
not specifically determine whether dilution of the medium increased the
synthetic rate of the cells, in addition to enhancing their rate of discharge
(although this is implied by their degranulation in the presence of
cyanide) ; certainly, in P. ktipinna transferred to freshwater from dilute
seawater, plasma sodium falls through the range of concentrations employed by Sage concomitantly with the onset of increased discharge and
synthesis in the prolactin cells ( Ball, 1967, 19eQ).
2. ACTH CELLS (CORTICOTROPS, L CELLS, OR X CELLS)
The ACTH cells, characteristically disposed in a sheet at the interface
between the rostra1 pars distalis and the neurohypophysis (Figs. 1 and
2), have been recognized morphologically in teleosts for many years (see,
e.g., Bock, 1928; Kerr, 1942a,b; Vervoort, 1957), but their significance
was not known. Some workers thought that they were aberrant or immature forms of the 9 cells (Bock, 1928; Vervoort, 1957; cf. Follenius,
1963a), while Bugnon ( 1960a,b) suggested they might represent the pars
tuberalis of higher vertebrates (cf. Wingstrand, 1966a). In recognition of
their enigmatic nature, Olivereau (1963b) termed them the “X cells.”
In Poecilia, the L cells are usually truly chromophobic (that is, without granules that can be stained by any of the standard dyes or histochemical techniques ) ; but sometimes they display a very fine, powderlike
granulation, faintly staining with erythrosin in Cleveland Wolfe or A& B
preparations, or with azocarmine in the Azan technique. They may also
stain a faint purple after Aliz B or gray with lead hematoxylin ( PbH).
They are elongated cells, usually arranged with the long axis perpendicular to the adeno-neurohypophysial interface. The cells are small, and the
absence of distinct granulation makes it difEcult to discern the cell outlines. The most characteristic feature in this species is the elongated
nucleus with a distinctive scattering of chromatin which gives the nucleus
an easily recognizable spotted appearance. The nucleolus in most normal
cells is insignificant or undetectable (Figs. 3 and 12; see also Fig. 13).
In the eel (Fig. 14) the L cells are much better granulated than in
Poecilia, and the granulation stains weakly with erythrosin and quite
strongly with Alizarin blue. The granulation is also strongly stained by
PbH which picks out the cells easily, although it is not a specific stain for