Oct, 1915.] b. JfA YATA.-1 'AN PBOSAPTIA PBOPERL ) BE PLAl ED l.i 



My opinion regarding Prosaptia is quite different from the 

 general view of" the leading authors, and I rather incline to 

 the statement of Smith, who regards it as referable to Poly po- 

 dium. For convenience sake, I shall here state my conclusion, 

 before I go into details as to my reasons therefor. My opi- 

 nion is that Prosaptia bears too close affinity to Polypodium 

 to permit its separation from the latter genus, and that it 

 differs from Davallia so widely that to assign it to the latter 

 would at once entirely violate what we call the natural sys- 

 tem. In other words, Prosaptia is really a Polypodium and 

 only imitates Davallia. It is a fern nearly the same as Poly- 

 podium in its phylogeny ; but it is absolutely different from 

 Davallia in its derivation. 



The present question as to the natural position of Prosap- 

 tia has arisen in my mind, since my discovery, in Formosa, of 

 a new fern, Polypodium urceolare Hayata 1 ', which very closely 

 resembles Prosaptia contigua in every respect, but has a fru- 

 ctification tending more toward Polypodium ohliquatum than 

 toward the Prosaptia. This has led me to examine the new 

 plant more closely in its vegetative and propagative organs. 

 The sori are under the margin of the frond, have orifices which 

 open obliquely on the under surface, and are margined with 

 elevated ridges beset with bristles. Thus they are of a form 

 just intermediate between Prosaptia contigua and Polypodium 

 ohliquatum. The gap in respect of generic characters, as re- 

 tained by Copeland, between the two genera is practically 

 filled by the presence of this new fern. 



The resemblance between this fern or Prosaptia contigua 

 and species of the subgenus Cryptosorus to which Polypodium 

 ohliquatum belongs is very remarkable, and of a kind which 

 no botanists ever dispute. The habit, the shape of the fronds, 

 and the structure of the hairs, scales and rhizomes are all the 

 same. The hairs are very peculiar; the\' consist of several elon- 

 gated cells, arranged in a single row, with very thick brownish 



1) An exhaustive description of this new specie^ is given in my Icones Plan- 

 tarum Formosanarum vol. V. p. 324. 



