150 
THE PERN FAMILIES OF BRITAIN. 
it from wliat were assumed to be spores, always, however, 
without success; and at length it was taken for granted that 
the peculiar growths produced by this Fern in the place of 
sori were merely abortive spore-cases, and that the plants, 
like some other abnormal forms, lacked the special vigour 
necessary for the formation of perfect reproductive spores. 
All further attempts at raising it were consequently abandoned; 
and only two divisions of the plant exist.* In the autumn 
of 1883 I discovered upon another Athyrium {A. F.-f., var, 
plumosum divaricatum), numerous proliferous bulbils, occupying 
the place of sori on the back of the fronds, and, re- 
porting this to Mr. Gr. B. Wollaston, he was led to re-examine 
A. F.-f. Clarissima — as the Fern in question had been named 
by Col. Jones — and came to the conclusion that these so far 
barren excrescences might be viviparous growths of a kindred 
nature, and capable of reproducing the parent form by direct 
bud-development. A portion of a frond was consequently sent 
to me, and upon examining it under the microscope, I found 
that there were very material structural differences between 
the unmistakable bulbils of A. F.-f. divaricatum and the 
singular growths upon A. F.-f. Clarissima, the former being 
solitary, bud-like growths, seated in the centre of a number 
of brown, lanceolate scales, and without a trace of indusium; 
while the latter were composed of five or six or more flask- 
shaped bodies, each one larger than the bulbils aforesaid, 
and seated within an undoubted indusium. The masses were 
sufficiently large for their formation to be clearly distinguish- 
able by the naked eye, covering more than the space of an 
ordinary sorus. At this stage no signs of spores or spore- 
cases could be detected, nor could any axis of growth be 
perceived ; so that it was impossible to form any theory as 
to the eventual mode of reproduction which might result ; 
for although the tips of the flask-shaped pseudo-bulbils were 
in some cases elongated into filiform processes, no sign of 
* It is, of course, open to question whether the excrescences formed prior to 
1883 were of exactly the same nature. Col. Jones inclines to the belief that they 
approached more nearly the character of sori, and did not in previous years present 
the same appearance as now described. 
