oet, wis.] a ua YATA.—CAN PROSAPTIA PROPERLY BE PL U ED ET 



reason, it was regarded by Fee as representing the special 

 genus, Cryptosorus. The sorus is located in a pouch-like cavity 

 immersed in the tissue of the fronds on the under surface, which 

 cavity has an orifice beset with bristles. Fee 1 ', in establishing 

 the special genus for this fern, explains "Ce genre, dont nous 

 ne connaissons que deu especes, a le port des Polvpodium 

 pectines, ct les sporotheces occupent aussi le sommet de nervil- 

 les simples. Le caractere distinctif qui motive la formation 

 d'un genre, se deduit de la situation des sporanges naissant 

 au-dessous de la cuticule inferieure pour se mettre en rapport 

 avec la lumiere ; ils la fendillent et il en resulte une ouverture 

 beante a peu pres ellipsoide et a marges epaissies. Les groupes 

 que forment les sporanges sont epars, distants, peu nombreux, 

 situes principalement vers sommet des lobules. Dans le C. 

 Dionsea, l'ouverture du meat est borde de cils convergents, et 

 qui se ferment a. la maniere des poils de la feuille du Dionsea 

 muscipula L. Ouelques Polypodium ont des sporanges loges dans 

 une depression de la lame ; mais l'est une fausse immersion, car 

 ils sont superficiels et non sous-cuticulaires." According to the 

 author, the sori develop in the following manner ; they are in 

 the beginning formed under the epidermis (" cuticule ") from 

 which, when fully developed, they at length break out; the slits 

 in the epidermis are the orifices of the pouch-like cavities. 



In order to assure myself of what is stated b\- Fee, I 

 looked in my very rich collections of the same fern, and 

 was so fortunate as to find that the fern is characterised by 

 indefinite growth, several stages of sorus-development being 

 represented in one and the same frond. On the basal portion of 

 the frond, I found full-grown sori and in the upper portions 

 half grown ones ; while, in the uppermost portions of the same 

 frond there appeared the very beginning of sorus-formation. 

 In the beginning, the sorus looks like a mere depression of the 

 surface ; this depression grows larger and deeper, aud becomes 

 cup-shaped. Sporangia then first appear at the centre of the 

 cup. The depression grows still deeper ond larger, but the 



1) Fee, A. L. A.— Geuera Filicum, Exposition des Genres de la Famille des 



Polypodiacees, p. 231. 



