are phtigocyt,ic. but Smith ( I 970a) considercd that only the hyaline
amoebocytc will phiigorytosv carbon particles. Anderson (1971) found
that phagwytosed material was subsequently released through the
branch ial epithelium.
(d) &pwt-rin!l cells (Fig. 1 9 ~ ) . ‘I’hcre are t,hree types of vesicular or
vacuolated cell in the blood named respectively “ signet-ring ”,
“ compzlrtmcwt ” tind “ morula ”. Signet-ring cells are about 8 p to
10 p in cliamctm and caontain a single large vacuole which presses the
cytoplasm a i d nucleus to the periphery of the cell. The vacuole contains granulrs in Brownitin movement, and the periphery is lined by
electroil cieiirJr material (Overton, 1966 ; Kalk, 1070). Signet-ring cells
appear to be derived from hyaline amoebocytes (Kalk, 1963b) and
according to Andrew ( 1 961) have fine protoplasmic processes extending
from them and giving them specific adhesive properties. In the transition from hydine arnoebocytc to signet-ring ccll there is an intermediate
vacuolated cmoebocyte.
(e) Compartment cell (Fig. 19b). These are about 8 p in diameter with
several vacuoles filling most, of the cell and providing the compartr
rnented tLpp(’iiran(’c. Each vacuole contains an accumulation of
granular material which in some species has a greenish appearance.
According to Kalk (1!,63b) the vacuoles of the compartment cell are a
new development arising in the cytoplasm of the signet-ring cell and
extracting material from the liirgc vacuole of that cell. This would
explain the itl>l)thre1lt anomaly in Endcan’s ( I 960) description of these
cells. He sttttes “ Emh (cell) vontains a large vacuole which varies in
size from ccll to cell . . . A number of suhpherical compartments,
peripheral i l l position, obscure the vacuole except at one pole of the
cell. ” Clwrly these w e trirnsitional stages toward the completed
compartmental cell.
(f) :lTordn cells (Chew cell type) (Fig. 19c). These celle which are 8 to
10 p iii diameter ~tre tightly packcd with granule filled globules or
vacuoles measuring 2 to 3 p in diiimeter and called vunadophores hy
Gander ct 01. ( I 963). When rc~leased from the blood stream and after
standing a short wliile they takr on zl berry-like appearance, perhaps
due to distortion of‘thr globulcs, and it8 is this appearance which has
cauxed them to be c d e d morirla cells. Due also to the fact that in some
cases they are known to contiiin vundium (Henze, 1913 ; Wcbh, 1939,
1956) and in others to contain iron (Entlean, 1053) they have been
reepectively termed vanadocytes wid ferroeykes. There is a need to
rationalize this terminology, particularly in view of the discovery of
niobium and titanium i n some spccki of ascidiaii. Although the mulberry-like appearance only appears after freeing of the cell from the
amoebocytc will phiigorytosv carbon particles. Anderson (1971) found
that phagwytosed material was subsequently released through the
branch ial epithelium.
(d) &pwt-rin!l cells (Fig. 1 9 ~ ) . ‘I’hcre are t,hree types of vesicular or
vacuolated cell in the blood named respectively “ signet-ring ”,
“ compzlrtmcwt ” tind “ morula ”. Signet-ring cells are about 8 p to
10 p in cliamctm and caontain a single large vacuole which presses the
cytoplasm a i d nucleus to the periphery of the cell. The vacuole contains granulrs in Brownitin movement, and the periphery is lined by
electroil cieiirJr material (Overton, 1966 ; Kalk, 1070). Signet-ring cells
appear to be derived from hyaline amoebocytes (Kalk, 1963b) and
according to Andrew ( 1 961) have fine protoplasmic processes extending
from them and giving them specific adhesive properties. In the transition from hydine arnoebocytc to signet-ring ccll there is an intermediate
vacuolated cmoebocyte.
(e) Compartment cell (Fig. 19b). These are about 8 p in diameter with
several vacuoles filling most, of the cell and providing the compartr
rnented tLpp(’iiran(’c. Each vacuole contains an accumulation of
granular material which in some species has a greenish appearance.
According to Kalk (1!,63b) the vacuoles of the compartment cell are a
new development arising in the cytoplasm of the signet-ring cell and
extracting material from the liirgc vacuole of that cell. This would
explain the itl>l)thre1lt anomaly in Endcan’s ( I 960) description of these
cells. He sttttes “ Emh (cell) vontains a large vacuole which varies in
size from ccll to cell . . . A number of suhpherical compartments,
peripheral i l l position, obscure the vacuole except at one pole of the
cell. ” Clwrly these w e trirnsitional stages toward the completed
compartmental cell.
(f) :lTordn cells (Chew cell type) (Fig. 19c). These celle which are 8 to
10 p iii diameter ~tre tightly packcd with granule filled globules or
vacuoles measuring 2 to 3 p in diiimeter and called vunadophores hy
Gander ct 01. ( I 963). When rc~leased from the blood stream and after
standing a short wliile they takr on zl berry-like appearance, perhaps
due to distortion of‘thr globulcs, and it8 is this appearance which has
cauxed them to be c d e d morirla cells. Due also to the fact that in some
cases they are known to contiiin vundium (Henze, 1913 ; Wcbh, 1939,
1956) and in others to contain iron (Entlean, 1053) they have been
reepectively termed vanadocytes wid ferroeykes. There is a need to
rationalize this terminology, particularly in view of the discovery of
niobium and titanium i n some spccki of ascidiaii. Although the mulberry-like appearance only appears after freeing of the cell from the