SECT. I. ORGANOGRAPHY AND GLOSSOLOGY. 77 



distinct appellation, and are called " Fronds ;" and that 

 part of a frond which is analogous to the petiole, is 



termed the " Stipes." In some cases, as in the tree 

 ferns of tropical climates (fig. 75.), the bases of 

 the decayed fronds form a tall trunk, which is termed 

 their " caudex ;" but when this portion creeps upon the 

 ground, as in the humbler forms of our own climate, it 

 has received the name of " rhizoma." In several 

 tribes the fronds possess nerves, but in many cases they 

 are composed entirely of cellular tissue. The vernation 

 of the fronds of most ferns is peculiar, and termed 

 " circinate " (fig. 72. #). It consists in having all 

 the extremities of its different subdivisions, as well as 



