(4
(b)
PIG. 30. The neural gland of Cionfc intmtinelis showing (a) the rotiodated phase and (b)
the oom~imt, phwe. a. glantlular tirwue; 1s. blood r?peoe; ci, star-shapecl cells
accumulating in the lumen of thn gland. (Reproduced with pmnimion, from
GeorGR. 1971.)
and turgidity of the gland increases there is a discharge of cellular
material from the gland. PBrb is emphatic that the ciliary current8 are
such that material can be carried out of the gland to the pharynx, and
he recognizes three stages in the cycle : (1) The reticulate stage with
empty gland ; (2) proliferation, sloughing and vacuoiization ; (3) digcharge of the gland and return to the reticulate phase.
More recently the fine structure of the epithelial cells and their
cycle of activity has been studied with the aid of electron microscopy
by Swan and Olsson (1965), Chatribost (I969), George8 (1967, 1970,
1971) and Lane (1971). The epithelium iR separated from the neigh-
(b)
PIG. 30. The neural gland of Cionfc intmtinelis showing (a) the rotiodated phase and (b)
the oom~imt, phwe. a. glantlular tirwue; 1s. blood r?peoe; ci, star-shapecl cells
accumulating in the lumen of thn gland. (Reproduced with pmnimion, from
GeorGR. 1971.)
and turgidity of the gland increases there is a discharge of cellular
material from the gland. PBrb is emphatic that the ciliary current8 are
such that material can be carried out of the gland to the pharynx, and
he recognizes three stages in the cycle : (1) The reticulate stage with
empty gland ; (2) proliferation, sloughing and vacuoiization ; (3) digcharge of the gland and return to the reticulate phase.
More recently the fine structure of the epithelial cells and their
cycle of activity has been studied with the aid of electron microscopy
by Swan and Olsson (1965), Chatribost (I969), George8 (1967, 1970,
1971) and Lane (1971). The epithelium iR separated from the neigh-