226 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



plants were treated with a boiling concentrated solution of 

 corrosive sublimate the cells retained their natural position 

 and size, at least sections from material treated in this man- 

 ner presented apparently a normal appearance. Asa mount- 

 ing medium twenty per cent, glycerine in water was found 

 to act very satisfactorily; but this was afterwards super- 

 seded by Farrant's Medium, on account of the easier 

 manipulation. 



The shape of the younger fronds of P. variegata is ob- 

 ovate. The larger fronds are more or less lanceolate, and 

 are but seldom lobed, though a few cases were noted in 

 which the frond exhibited considerable lateral development, 

 together with a much laciniate appearance. The fronds are 

 slightly undulate and possess as a rule a cuneate to obtuse 

 base. A few specimens exhibited a cordate base. The 

 plants are attached by a small disc, surrounded by a slight 

 aureole. In this regard the plants differ from the descrip- 

 tion given by Kjellman, who calls them substipitate. How- 

 ever, a careful examination of our specimens has failed to 

 reveal a single instance of this. 



The sterile frond has a red-purple color, but the fertile 

 frond presents a variegated appearance, especially towards 

 the center of the frond, while along the edges it is a rich, 

 uniform crimson, sharply contrasting with the yellowish 

 rim, some two to three millimeters broad, which surrounds 

 the fully ripe frond till near the base. This yellowish rim 

 consists of an empty network of gelatinous cell-walls, which 

 formerly contained the carpospores. The latter, when ripe, 

 left the frond because of the partial dissolution of the sur- 

 rounding cell-walls. This network is full of infusoria. 



The crimson edges consist almost entirely of sporocarps, 

 with but few vegetative cells intermixed ; while the varie- 

 gated appearance of the central part of the frond is due to 

 an intermixing of groups of deeply stained sporocarps with 

 a greater or lesser number of colorless vegetative cells. In 

 the sterile frond the vegetative cells are all colored, but not 

 intensely so. It has been suggested that the lack of color in 



