FILIC1NEAE. MARATTIACEAE. 251 



Vegetative propagation is effected in Ophioglossum by adventitious buds on the roots ; 

 O. pedunculosum is monocarpic, since it dies down as a rule after it has formed fertile 

 leaves, but it maintains its existence by means of root-buds according to Hofmeister. 

 Most species, reckoning from the base of the stem to the tip of the leaf, are only from 

 five to six inches high; some may be a foot in height; Botrychium lanuginosum, an 

 Indian species, is said by Milde to grow to the height of three feet ; its leaf is tripinnate 

 or quadripinnate, and the stalk contains from ten to eleven vascular bundles. 



2. MARATTIACEAE 1 . 



The formation of the prothallium in the Marattiaceae agrees in its main features 

 with that of leptosporangiate homosporous Ferns, and resembles especially that of 

 the Osmundaceae. A cell-surface or a body of cellular tissue is the first product of the 

 germinating spore, and ultimately a deep-green heart-shaped prothallium is formed 

 with a hemispherical projecting cushion of tissue on its under side. The anther idia 

 are sunk in the tissue as in Ophioglossum and as a rule in all eusporangiate Ferns, 

 and are placed on the upper and the under side, but especially on the cushion on the 

 under side of the prothallium. A superficial cell divides by a transverse wall into an 

 upper cell, the lid-cell, and a lower which is the central cell of the antheridium. The 

 latter divides into a large number of mother-cells of spermatozoids (spermalocytcs] ; 

 the lid-cell also is divided by walls at right angles to the surface of the prothallium. 

 Tabular cells to form the parietal layer are cut off from the cells surrounding the 

 central cell of the antheridium. The central and youngest of the lid-cells is broken 

 through when the antheridium is mature, and allows the escape of the spermatozoids. 

 The antheridia appear when the prothallia are some months old. 



The archegonia are on the cushion on the under side of the prothallium as in the 

 other homosporous Ferns. Their development agrees with that of the rest of the 

 Ferns, but they are so deeply sunk in the prothallium that the neck scarcely projects 

 above its surface. The canal cell of the neck divides, according to Jonkman's figures, 

 by a transverse septum ; indications of this proceeding, that is, of the division of the 

 nucleus of the canal cell, but without the appearance of a cell-wall, have been 

 observed by Strasburger in other Ferns (see Fig. 151 of P fen's scrrulaia}. 



The second or asexual generation (sporophore, sparophyfe). TLe development 

 of the embryo is unknown, but it may be assumed to be in conformity with the rest of 

 the Ferns, with which the Marattiaceae agree also in habit. The stem is usually erect, 

 short, thick and tuber-like ; the leaves that spring from it are 1 uge, on long stalks, 

 crowded together and spirally arranged, with pinnatifid or sometimes palmatifid 

 laminae ; the resemblance to the true ferns is greatly increased by the circinate folding 

 of the leaves in the bud, which unroll slowly from below upwards. 



The stem of Marattia and Angiopteris reproduces on a larger scale the mode of 

 development of the stem of the Ophioglosseae ; it grows erect without reaching any 



1 De Vriese et Harting, Monographic cles Marattiacees, Leide et Diisseldorf, 1853. Ltirssen's 

 researches are given in his Handb. d. system. Bot. i Bd. Leipzig, 1879. Russow, Vgl. Unters. 

 1872, p. 105. Tschistiakoff, Materiaux pour servir a 1'histoire de la cellule vege'tale (Ann. d. sc 

 nat. 5 ser. T. XIX). Holle, Ueber d. Vegetationsorgane d. Maratt. (Bot. Ztg. 1875, p. 215). 

 Goebel, Beitr. z. vergl. Entwicklungsgesch. d. Sporangien (Bot. Ztg. 1881). De Bary, Vergl. 

 Anatomic, Leipzig, 1877. Jonkman, Ueber d. Entwicklungsgesch. d. Prothall. d. Maratt. (Bot. 

 Ztg. 1878, p. 129); Id. Die Geslochtsgeneratie dcr Maratt. mil 4 Tafeln (Holland). 



