XXIl] 



ANATOMY 



157 



Fig. 44 r. Disposition of the sporangia of the Sell I /.acaceae. .-JjS. dichotoma]. Sm., part of a fertile 

 segment (sorophore). B, C, Lygoditiin japoiiidtm S\v. B, apex of a young fertile segment. 



C, mature fertile segment, at (x) the flaps have been removed so as to display the sporangia. 



D, Mohria caffrorum (L.) Desv. , segment of a fertile pinna. E, F, Anemia Phyllitidis Sw. 



E, side view of a young fertile segment. F, fertile segment from below. {A, B, E, after Prantl, 

 C, D, F, after Dlels, from Engler and Prantl.) 



Anatomy 



The Schizaeaceae have great diversity in the habit of the shoot, from the 

 creeping- rhizome with its laxly disposed leaves to the ascending or upright 

 stock with leaves crowded and densely spiral. The internal structure also 

 shows marked differences, which follow the external form. In fact the 

 Family is as varied in its stelar structure as that of any in the whole Class of 

 Ferns. The simplest adult structure is found in Lygodiuni, for there the 

 rhizome is traversed by a protostele with solid xylem consisting of tracheides 

 and scattered parenchyma, surrounded by phloem, pericycle, and endodermis. 

 There is no typical protoxylem : the first-formed tracheides are finely 

 scalariform, and are scattered round the periphery of the xylem-core (Fig. 

 442). (Boodle, Ann. of Bot. p. 359, 1901; and p. 511, 1903.) The petiole is 

 traversed by a single strand, which comes off from the protostele with 

 only superficial disturbance of it: in fact the adult plant retains the simple 

 relation between the protostele and the trace which is seen in the sporeling. 

 The foliar strand in the climbing petiole of Lygodiuiii is almost cylindrical, 

 with bays of phloem protruding into the xylem (Vol.1, Fig. 165,^). There 



