supporting lamella

HISTOLOGY AND DEVELOPMENT OF MTRIOTHELA PHBYGIA. 515
In the further history of the gonophore I am only concerned
with one point, namely, the fate of the primitive germ-cells.
I entirely agree with Allmann that in their earliest history it
is impossible to distinguish between male and female gonophores.
Position does not help one, for, as has been recognised
before, both male and female elements are produced on the
same blastostyle, and to a certain extent indiscriminately, the
same transverse section frequently passing through both male
and female gonophores. Very soon, however, the male gonophores
become distinguished by the rapid proliferation of their
generative elements.
In the female gonophore at some period, often relatively late,
two or three of the generative cells become larger and more
prominent than the others. The period at which this happens
does not appear to be fixed; and whatever factor it may be,
whether something inherent or accidental, that determines
which of these struggling cells shall obtain the mastery and eat
up its fellows, it sometimes does not come into play until the
gonophore has become a well-formed structure. But it is quite
late in the history of the gonophore, when that structure is
large and already swollen with yolk, before these two, three
or four cells, which, so to speak, have succeeded in attaining to
the final heat, decide who is the winner.
In the facts which have been set down above with regard to
the structure of the ectoderm of the blastostyles, and the formation
of the gonophores, two main points appear to me to be
of special significance. These are (1) that the gonophore
appears to be a curiously modified bud, and (2) that the generative
elements pre-exist as free cells having lodgment in the
tissues of the adult, and only travel into the abortive bud,
which is their place of final development.
maternal tissues, and not to the gonophore bud. They are, therefore, not
included in the above statement.