I02 



MARATTIACEAE 



[CH. 



also frequent anastomosis of the separate strands, and a further source of 

 confusion Hes in the formation of roots in relation with the internal meristeles, 

 and the threading of the root-traces through the rest on their way outwards 

 (Fig. 397; compare also Fig. 391). It will be unnecessary to describe the 

 details of these complex arrangements : it must suffice to bring them into 

 relation with the less complex structure of other Ferns, and with that of the 

 cognate fossils. This is most readily done by reference to the sporeling: for 

 there the axis is found to be traversed by a coherent monostele: and it is 

 to the disinteg-ration of this, together with the formation of commissural 



Fig- 397- Angiopteris eveda. Transverse sections of stem. A was taken from the region of its greatest diameter; 

 here the vascular system is polycyclic and highly segregated into separate strands. B was taken at a level above 

 A, from a region formed under less favourable conditions, with fewer leaves and less bulky axis. The vascular 

 system is still polycyclic, but the strands are less highly segregated. (After Mettenius. Natural size.) 



connections, that the complex structure of the adult is due. A striking 

 feature of the Family is the absence of endodermis in the adult state. In the 

 sporeling the stele is delimited as usual : but the endodermis is not continued 

 upwards. The Marattiaceae share this detail with OpJiioglossitm, and it is 

 noteworthy that in both the foliage is of a leathery texture. (See Vol. I, 

 Chapter vii, p. 135.) 



The monostele of the sporeling has been shown to be, as in other Ferns, 

 protostelic at first in Danaea alata (West), and Marattia alata (Charles), 

 and others. This is probably general. It expands upwards into a dictyostele 



