202 LYCOPODIALES [CH. 



The difference between the original surface of a Sigillaria 

 stem and that of partially decorticated specimens is seen in 

 figs. 196, C and D ; in fig. C the bark of Sigillaria Brardi 

 shows the characteristic wrinklings of the superficial tissue, 

 while at a slightly lower level the leaf-scars are replaced by 

 the parichnos casts, a, and fine longitudinal striations represent 



9: A 



^. f 



FiQ. 197. Carica sp. From the Royal Gardens, Kew. (Much reduced.) M.S. 



the elongated phelloderm cells laid bare by the exfoliation of 

 the surface-layers. Similarly, in the rib of Sigillaria laevigata 

 (fig. 196, D) the parichnos arms, p, and the longitudinal stria- 

 tions are exposed at the lower level, while the surfixce is smooth 

 and bears rows of widely separated leaf-scars. 



