214 
APOSPORY IN FERNS. 
spermatozoids which, aided by the moisture, w'hich in a con- 
genial atmosphere is deposited upon the under surface of the 
prothallus, make their way to the archegonium and fertilize the 
ovary seated at its base, the result being a plant resembling the 
fern from which the spore originated. From this description it 
will be seen that the prothallus represents the flower of the 
higher orders of plants in so far that it bears the homologues of 
the stamens and stigma in the forms of the antheridia and 
archegonia, and also the ovary and ovum. The spermatozoids 
take the place of the pollen grains, but seem endowed with a 
certain amount of volition in addition to power of locomotion, as 
they have been observed to travel direct towards the archegonia, 
and I am informed by Prof. F. 0. Bower that they have made 
their way unmistakeably towards simulated archegonia, con- 
sisting of minute applications of malic acid to the surface of the 
prothallus, a fact which points to sensory organs of some sort. 
It will be seen from the preceding remarks that in the 
normal development of ferns the prothallus constitutes a separate 
generation, and it would therefore form an approach to the 
higher orders of plants, did the prothallus spring direct from 
the parent plant, instead of through the mediation of the spore; 
since the fern would then be the bearer, if not of flowers proper, 
at any rate of their homologues. 
This phenomenon then, viz., the production of the prothallus 
upon the parent plant without the mediation of the spore — i. e., 
apospory — is precisely that which has rendered Colonel Jones’ 
Athyrium Filix-fcemina, var. Clarissima, so remarkable, since it 
is upon that plant that this peculiarity has been first observed. 
In connection with this discovery I may mention that Prof. 
Thiselton Dyer considers that it exhausts the obvious possibiliiies 
with regard to the reproductive methods of ferns ; he also recounts 
the various steps which have led up to it, and gives the dates 
and discoveries thus : — As far back as 
