FILICINEAE.—MARA TTIA CEAE. 



253 



forms an anterior and a posterior chamber, separated from one another by a 

 longitudinal wall, the commissure, as is seen in Fig. 206 ; the leaf to which 

 the stipule belongs lies rolled up in the posterior chamber, and the two posterior 

 wings of the stipule unite over it ; the chamber formed by the anterior wings encloses 

 all the younger leaves. These peculiar stipules continue fresh and succulent, and 

 adventitious buds may even be produced from them, not only during the lifetime of 

 the unfolded leaves, but after they have fallen. 



The roots, as Fig. 205 shows, arise close beneath the growing point of the stem, 

 one at least, it would appear, at the base of each young leaf ^; from hence they grow 

 obliquely downwards through the succulent parenchyma of the stem and of the older 

 basal portions of the leaves, and at length emerge much lower down between them 

 or out of a leaf-scar. The roots are less numerous, thicker, of more delicate consistence 

 and of a lighter colour than in most of the true Ferns ; in these points they agree with 

 the roots of the Ophioglosseae. Beneath the ground they branch copiously and, like 

 those of other Ferns, monopodially. 



The leaves, which in the smaller species are from one to two, in the largest 

 {Angioplerts) from five to ten feet in length, have a long 

 and very strong petiole grooved on the inside, and a com- 

 pound lamina which is pinnate or bipinnate, or in Kaulfiissia 

 palmate. The primary petiole has an enlargement at the 

 point where it unites with its base, the secondary petioles 

 also where they join the primary, and the leaflets where 

 they join the rhachis have a similar swelling, as in the 

 Leguminosae. 



The Marattiaceae are distinguished from the glabrous 

 Ophioglosseae by a growth of hairs, which however is scanty 

 as compared with that of the true Ferns. 



The sporangia of the Marattiaceae are formed in large 

 numbers on the under side of ordinary foliage-leaves which 

 undergo no metamorphosis. They are placed, as in most 



of the true Ferns, on the veins of the leaves, and usually form two rows of sori, 

 which cover the veins running from the mid-rib to the margin of the leaflet either 

 along their whole length, as in Danaea, or towards the margin only as in Angiopteris 

 and Marattia ; in Kaulfussia they are on delicate anastomosing veins between the 

 mid-rib and the lateral vein. The sorus is attached to a cushion-like outgrowth of 

 the tissue of the vein, the placenta. In Angiopteris only the individual sporangia of 

 a sorus are free, not having grown together into a compound structure ; they are 

 ovoid in shape and without stalks, and they open when ripe by a longitudinal fissure 

 on the inside (Fig. 207 A)\ if we imagine the sporangia in each longitudinal row in 

 a sorus united together, and the two rows adhering to one another by their inner 

 surfaces or fused together, we shall have such a structure as we find in Marattia (Fig. 

 207 B, C). That we are not dealing in this case with a sporangium with several 

 compartments in two rows, but with a sorus formed of two rows of sporangia united 

 together by their sides, is shown both by the history of development and by comparison 



Fig. 206. Base of a leaf-stalk 

 St with the stipules cut through ob- 

 liquely ; V the anterior, h the pos- 



united by a commissure c where the 

 anterior and posterior wings meet. 

 Natural size. 



' According to HoUe there is one root to each leaf in Marattia, tsvo in Aiigioptc 



