69 
it is not, as Lcistrcm is, primitive, and that it is not so . particularly 
fitted to any set of widespread conditions— as Polypodium is to the 
epiphytic habitat— that it can become dominant under them and then 
become further specialized under peculiar subordinate conditions. 
Of our fern genera, only two, : 8 colop endrium . and Stenochlaena, can 
be treated at all positively as derived from Asplenium. The case of the 
former is already well known. Tf my S. pinna-turn is what it is called, 
which I do not' doubt, the genus Triphlebia owes its origin to an error, 
for its sori originate exactly as in S. vulgare. 
Asplenium epiphyticum is a fern described from material collected 
on the Gulf of Davao. It is common along the lower border of the 
high forest at San Ramon, and I have now specimens from Surigao. Its 
resemblance to some other scandent Asplenia with simple fronds was 
strong enough to demand some care in the diagnosis ; yet Christ says 
it is unnfistakably Stenochlaena, and, indeed, its . vegetative structures, 
root,' stem, and leaf, are apparently identical with those of occasional 
immature forms .of S. aculeata (Blume) Kunze. 35 Knowing a fern as 
well, as I do this one, and never having seen any indication, that it is 
other than Asplenium in its fruit, or has any other structures that as 
an Asplenium it might not have, I canonly believe it to.be an Asplenium ; 
but neither can the affinity to Stenochlaena he mistaken.. In my opinion 
we have in S. aculeata a very striking and perfect example of the repeti- 
tion in the development of the individual of the race-history .of Steno- 
chlaena, proving beyond any doubt that it is an offshoot of Asplenium. 
The remarkably complete preservation, of the race-history in this case 
is because the forms which are gone through are themselves well adapted 
to the. environment. 
It is not impossible that Goniogramme is also an offshoot of Asplenium, 
but the. evidence- on which any particular ancestry might.be ascribed to 
this genus and to Syngramma is still inadequate. 
; The Pteridew are so . poorly represented in the Philippines that a 
discussion of the affinities of most of the group is not called for here. 
I have already pointed out the interesting position of, Schizostege as a 
probable ancestor of Pteris and Gheilanthes. The genus was first de- 
scribed by Hillebrand from a very rare Hawaiian plant. Baker reduced 
it to Gheilanthes, - and Christ, with rather better reason, transferred it 
to Pteris. My Mindanao plants agree in every essential character with 
the Hawaiian, but in aspect incline . toward Gheilanthes, rather than 
toward Pteris. In the irregular and imperfect marginal anastomoses, 
Schizostege stands directly between Gheilanthes and Pteris. Its antiquity 
is attested by its discontinuous distribution. The resemblance of S. 
Lydgatei to. P. quadriaurita suggests that the latter may be the most 
primitive form of Pteris, and this idea receives some support from the 
35 Underwood : The Genus Stenochlaena. Bull. Torr. Bot. Club. (1906), 33:40. 
