PART 11. CHAPTER XX. 



249 



Recent Tree-Ferns. 



genus Sigillaria, were true arborescent ferns, as for example, 

 that section which has been named Caulopteris by Lindley and 

 Hutton. (See Fig. 251.) But these are comparatively rare, 

 whereas of the other section (Fig. 252.) more than forty species 

 have been described. In these the scars on the stem are smaller 

 and more regularly arranged in parallel series on the fluted 

 bark. (Fig. 252.) 



The recent tree-ferns belong to one tribe (Polypodiacew,) and 

 to a small number only of genera in that tribe, in all of which 

 the surface of the trunk is marked with scars, or cicatrices, left 

 after the fall of the: fronds. These scars are precisely similar to 

 those of Caulopteris (Fig. 251); but Mr. Lindley objects to the 

 opinion that the remaining Sigillarise of Brongniart were Tree- 



Fig. 253. Fig. 254. Fig. 255. 



Living Tree-ferns of different genera. (Ad. Brong.) 



Fig. 253. Tree-fern from Isle of isourbon. 

 Fig. 254. Cytliea glaum, Mauritius. 

 Fig. 255. Tree-fern from Brazil. 



ferns, because the scars in these are smaller, dissimilar in form, and 

 more regularly arranged in parallel lines ; also, because the stems 

 are fluted, (see Fig. 252.) and sometimes bifurcating. M. Brong- 

 niart has replied, that the forking of the stems of some of the 

 fossil trees is no more than might have been expected from their 

 large size ; and as to the forms of the discs or scars from which 

 the fronds have fallen, their individual variations are not greater 



