POLYrODIACE.lO. 327 



genus to the later. His opinion is, in other words, that tlie fern so well 

 defined from others should be retained as a distinct geniis, however close 

 afiinity it niay have to Polypodium. 



Let me here state briefly jiist a few lines as to what constitutes Prosaptia. 

 It is a fern closely resembling Polypodium ohliquatum in many respects es- 

 pecially in its vegetative organs, but having a fructification nearly similar to 

 that of Davallia. Modern pteridologists, such as Hooker^\ B.UiER-^, Christ'^, 

 Chkistensek^' and Diels^', maintain tliat while Prosaptia is separable from 

 Polypodium, it is quite assignable to Davallia, and they ranlc down the 

 former to a subgenus of the latter. 



My opinion regarding Prosaptia is quite difierent fi-om the gcneral view 

 of the leading authors, and is rather iaclined to the statement of Smith, who 

 regards it as referable to Polypodium. For convenience sake, I shall here state 

 my conclusion, before I go into details as to my reasons therefor. My opinion 

 is that Prosaptia bears too close affinity to Polypodium to perrait its separation 

 from the latter genus, and that it diifers fi-om Davallia so widely that to 

 aaeign it to the latter woukl at oncc entirely violate what we call the natural 

 system. In other words, Prosapjtia is really a Polypodium and only iraitates 

 DavaUia. It is a fern nearly the same as Polypodimn in its phylogeny ; 

 but it is absolutely different from DavalUa in its derivation. 



Tlie present question as to the natural iiosition of Prosaptia lias arisen in 

 my mind, since my discovery in Formosa of the present new fern, Pohjpodium 

 urceolare Hayata (Fig 136 and 137, a-f ), which veiy closely resembles Prosaptia 

 contigua in eveiy respect, but has a fructiiication tending more toward Poly- 

 podium ohliquatum thau toward the Prosaptia. This led me to examine the 

 new plant more closely in its vcgetative and i^ropagative organs. Tlie sori are 

 under the margiu of the frond, liave orifices which open obliquely on tlie under 

 surface, and are margined witli elevated ridgcs beset with bristles. Tiius they 

 are of a form jast intermediate betweeu Prosaptia contigua and Polypodium 

 dbliquatum. The gap in respect of generic characters of the two genera as 

 retained by Copeland, is practically fiUcd by the presence of this new fern. 



1) HooKER, \V. .J. — Species Filicum I. i). 160. 4) Christensex, C. — Index FiUcuni, ]>. 589. 



2) Baker, J. G.— Synopsis Filicum p. 94. 5) Diels, L.— l.c. p. 212. 



3) Christ, D. — Famkriiuter der Erde, p. 305. 



