wo 
o 
ww 
ise 
MR. E. J. LOWE ON SCOLOPENDRIUM VULGARE. 
Report or Proressor F. O. Bower, D.Sce., F.R.S. 
The flat green expansions are portions of a fern-frond, they 
are not prothalli but show a vascular strand in the middle of 
the stalk when cut transversely and the tissues have inter- 
celiular spaces, which are absent in prothalli at their margins ; 
they have produced, by very prolific aposporous growth, pro- 
tballi with antheridia on the smaller ones, and on the largest, 
archegonia. The smaller plant with leaves shows again the 
aposporous development, prothalli originating from the margins 
of its leaves. I think this has already been recorded by 
Mr. Druery. 
Extract From A Letrrer or Proressor J. BRETLAND 
Farmer, F.L.S. 
As to the fern plants you sent me some weeks ago, it was 
from the edge of the stalked frond that the prothallium was 
developed. Thus [referring to a figure which is not reproduced 
here] the shadow portions represent the place where the out- 
growths occurred. It is very clear as the thickness of the 
frond suddenly diminishes there and the intercellular spaces 
which are characteristic of the leaf proper entirely disappear. 
{ should regard the case as being one of premature apospory 
if I may use such a term; I mean that the edge of a leaf too 
young (as regards the whole plant) to bear sporangia at all, had 
at once grown out to the other generation. What I had hoped 
to find and what would have settled the affair was dividing 
wuclei, for in the prothalloid generation these are only half the 
number of nuclear segments (chromosomes) as compared with 
those in the frond plant. I find it impossible in these sections 
cut by hand to prevent the prothalli outgrowth breaking away 
from the frond, and the series I was trying to embed and cut 
with the microtome unluckily did not succeed. Still, I have 
no hesitation in affrming that on these early fronds the pro- 
thalloid structures are developed as outgrowths from the edges 
or from the lower surface just within the edge of the frond. 
On the section I am sending you, which only includes the 
prothalloid outgrowth, you will notice archegonia on the upper 
surface of the prothallium. May not this account also for your 
getting plants from the middle of your prothalia ? 
