supporting lamella

534 W. B. HARDY.
integration of the sphere approaches completion, the vacuole
in which it lay becomes obliterated; or they may be rapidly
and entirely dissolved and discharged from the cells, the
vacuoles meanwhile persisting and leaving the striking honeycombed
appearance described above (fig. 22). Whatever may
happen to the constituents of the sphere in the first case,
which agrees with the fate of the nutritive spheres of Hydra
as described by Kleinenberg and Greenwood, we can only conclude
that in the second case they have been dissolved and
discharged into the enteric cavity. It is even possible that we
may divide the endoderm-cells, other than the gland-cells, into
two sets: (1) Those which are concerned in the elimination
of waste matter from the nutritive spheres or from the somatic
fluid directly. These are the apical cells of the villi and the
vacuolate cells in their immediate neighbourhood, And (2)
Those which discharge their stored material, leaving, so far as
can be detected, no residue. These lie towards and between
the bases of the villi in the blastostyles and middle regions of
the body and foot.
This conclusion, which may be accepted as a provisional
hypothesis until the processes taking place in the endoderm
shall have been worked out more fully, is based upon two facts;
namely, that the pigment, as was noted by Allmann, is located
only in the cells near the free ends of the villi, and that the
bubbly cells in all their various conditions of incomplete or
complete discharge always lie between or towards the bases of
the villi.
Another point of evidence in favour of the view that the
somatic fluid conveys stored nutriment from one part of the
body to another is derived from a study of the histology of the
spadix of the gonophores.
Structure of the Spadix of a Gonophore.—This,
in the completely formed female gonophore, is composed of
a considerable number of tongue-shaped villi, which have their
apices turned towards the axis of the spadix, and project
a considerable distance downwards towards the centre of
the blastostyle. The cells between their bases, and therefore