SOME PROBLEMS OF REPRODUCTION. 31 
The oosphere or “procarp” has a long trichogyne closed at the 
apex, and a basal enlargement containing the single nucleus. 
The spermatium adheres to the trichogyne and opens into it ;! 
its contents with the male pronucleus pass down; and since 
at this time two nuclei are seen in the base of the procarp, and 
only one shortly after, it is certain that the nuclei must fuse 
in the zygote. The trichogyne is then shut off, its lumen 
being encroached upon to obliteration by a centripetal growth 
of its cell-wall close to the base. Before and after fertilisation 
granules which react to stains like nuclear chromatin are 
present in the plasma of the trichogyne; and Schmitz 
identifies these with excreted nuclear fragments on purely 
a priori grounds, relying on the current theory of fertilisa- 
tion. But he adduces no real evidence as to their origin and 
nature. 
A peculiar process occurring in many Floridez is se- 
condary fertilisation, the zygote forming a new karyo- 
gamic union as a gamete with an “ auxiliary cell”’ or secondary 
oosphere ; or the zygote grows and branches with cell division, 
and its offspring play the part of secondary males to the 
secondary oospheres (Dudresnaya). In this way sometimes 
one spermatium indirectly fertilises several secondary oospheres 
—an economical process as yet unparalleled in nature; its 
explanation is probably to be sought in the motionless charac- 
ter of the male cells, and the inadequate adaptations for what 
we may almost term “ pollination.” 
In Corauiina the procarps with their auxiliary cells are 
collected into a disc; the central cells alone possess tricho- 
gynes, and are fertilised by the spermatia ; but as zygotes they 
have no power of development save to fertilise in turn the 
peripheral procarps, which have no receptive organs of their 
own. 
1 The following cytological details are taken from the account by Schmitz 
in ‘ Sitzungsber. d. Berl. Akad.,’ 1883, 215. 
