FILICINEM. 



417 



different ages (^, nb). The young leaves have a circinate vernation, and are com- 

 pletely invested by the stipules until the time when the petiole begins to elongate 

 and the lamina to unroll itself. Each pair of stipules belonging to a petiole forms, 

 as is shown in Fig. 291, ^ and B, an anterior and a posterior chamber, which are 

 separated by a longitudinal wall (commissure). In the posterior chamber lies the 

 rolled-up leaf, to which the stipules actually belong, the two posterior wings of the 

 stipules extending round it. The chamber formed by the anterior wings of the 

 stipules encloses the group of young leaves. This is the arrangement in Angiopkris, 

 and it appears from herbarium specimens to obtain also in Dancea, and from 



Fig. 291 B. — Basal portion of 

 a petiole st with the stipule cut 

 through obliquely ; v the anterior 

 and h the posterior wing; at the 

 junction of tlie anterior and pos- 

 terior wings the stipules are con- 

 nected by a coijimissure c (natural 

 size). 



Fig. 291 .<4.— Vertical section of the stem of a young An^iopteris evecta: above are the youngest leaves {b) still completely 

 surrounded by the stipules nb ; si petiole of an unfolded leaf with its stipule nb ; n, in every case the cicatrix on the basal 

 portion of the petioleyy, from which the upper portions have separated ; c c the commissures of the stipules in vertical section ; 

 ■w TV roots (natural size). 



drawings in Marattia. Harting's representation of the stipules is quite erroneous. 

 These peculiar stipules remain fresh and succulent not only during the life of the 

 leaves but also after they have fallen, and adventitious buds may originate from 

 them. 



The roots arise, as is shown in Fig. 291, A^ in the tissue of the stem 

 immediately below the growing-point. One arises apparently at the base of each 

 young leaf They grow obliquely through the succulent parenchyma of the stem 

 and of the older basal portions of the leaves, and finally reach the surface at a 



E e 



