65 
it can have originated elsewhere than in Lastrcea. The fertile frond 
is too reduced to offer any clue, but the sterile is altogether Lastrsea-like. 
As it is, so far as known, strictly endemic in the Philippines it is 
quite reasonable to look for its ancestry among the most similar Phil- 
ippine ferns. 
With the' same measure of probability, Stenosemia may be regarded 
as an offshoot of Aspidium , not, in spite of the sparingly anastomosing 
veinlets of Pleocnemia, but of Euaspidium. A. Griffitliii is a species, 
in the most similar Aspidium group, with “sori” anastomosing along 
the veins. Indusia, if present in the ancestral forms, would inevitably 
have been lost in the reduction of the fertile frond. Leptochilus must 
also be derived from Aspidium. L. lanceolatus is still occasionally 
found with the sporangia confined to the main veins (as in Loxo- 
gramrne) ; and L. latif dlius usually has the “sori,” at least until they 
are old, anastomosing along the veins instead of covering the frond, 
being in this respect like its possible relative Hemionitis. The insta- 
bility of the frond-form of. many, species of Leptochilus is a familiar 
phenomenon. 
If the W-oodsiece of the Naturlichen Pflanzenfamilien are a homo- 
geneous group, it has a common origin with the Aspidiece , the most 
primitive representatives of the two groups being much closer together 
in all respects than, either is to the highly specialized members of its 
own tribe. In fact, they are so alike that it is impossible to call either 
the more primitive, and I have ascribed that place to Lastrcea only on 
geographical grounds, and because it is now a great and conspicuous 
group. The primitive member of Woodsiece is Acrophorus. The gen- 
eralized character of this fern is shown by its history. Hooker, who 
calls it Davallia (§ Leucostegia) , remarks : 31 “Blume arranges it in Aspi- 
dium, and expresses no doubt as to the propriety of so doing. Presl 
makes a distinct genus of it, and places it between Cystopteris and Leu- 
costegia. Judging from his figure, I do not see how it differs from 
Davallia, but he says Tiocce genus Cystopteridi valde affine est, differt 
soris in venulis apicalibus,' and under Leucostegia he says ‘Acrophoro 
affinissimum est’ ” Diels 32 says of it “Habituell an Diacalpe erinnemd ; 
durch die gleichseitige Entwickelung der Segmente sowohl wie das Indu- 
sium von den Davallieen zu unterscheiden,” the indusium being “breit 
eiformig, am Grande angewachsen, sonst fra.” 
I have no doubt that all these authors were describing the same species, 
and that, so far as insufficient material is ever a justification, each was 
justified in his view as to. the affinity of the plant. When I first found 
the plant, hitherto unknown in the Philippines, I ascribed it to Lastrcea 
as unhesitatingly as Blume had done; but it is indeed strikingly like 
31 Species Filicum 1 : 157. 
32 Nat. Pflanzenfam. I, 4: 164. 
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