STRUCTURE. 
7 
twice, or several times; sometimes they are of tender 
texture, sometimes very wiry, and often in young plants 
clothed with hairs. The points of the roots and rootlets 
represent the mouths of the plant, and imbibe moisture 
for its nourishment. 
The caudex or stem is of various character, creeping 
or ascending . Mr. Newman draws a distinction between 
two kinds of creeping caudex, the one that terminates in 
a frond, and the one that does not ; calling the first a 
caudex, and the second a rhizome ; but other writers of 
equal celebrity do not require this distinction, so we 
need only make one division in the character of the 
caudex, that of the creeping and erect ones. The creep- 
ing caudex extends itself either upon or beneath the sur- 
face of the ground, soon becoming twisted and meander- 
ing in its manner of growth, and sending out branches 
in the style of an underground stem, it puts out single 
roots or clusters of roots at intervals, and throws up 
young fronds from the superior surface ; the creeping 
caudex is generally more or less clothed with scales. 
Creeping ferns are very easy of propagation, for any 
rooted branch is capable of living as a separate plant. 
The caudex of the Polypodium vulgare creeps on the 
surface of the soil, that of the P. Dryopteris , Phegopte- 
ris, and Rohertianum creep beneath the soil. An erect 
caudex increases from the summit, and in tropical climes 
attains a height of twenty, thirty, or even forty feet. 
In British ferns this is never the case : the erect caudex 
has merely a tufted appearance ; in many instances it 
throws out its fronds from its circumference, and each 
bending outwards with a graceful curve, those ferny 
crowns are formed which lovers of the beautiful so 
greatly delight in. In a few species, as the Oemunda 
