118 
ORGANOGRAPHY. 
BOOK I. 
are stronger than themselves. It was included by Linnaeus 
among what he called fulcra ; and has generally, even by very 
recent writers, been spoken of as a peculiar organ. But, as it 
is manifestly in most cases a particular form of the petiole, I 
see no reason for regarding it in any other light. It may, 
indeed, be a modification of the inflorescence, as in the Vine; 
but this is an exception, showing, not that the cirrhus is not 
a modification* of the petiole, but that any part may become 
cirrhose. 
In some cases the petiole of a compound leaf is lengthened, 
branched, and endowed with the power of twisting round any 
small body that is near it, as in the Pea : it then becomes what 
is called a cirrhus petiolaris. At other times, it branches off on 
each side at its base below the lamina into a twisting ramifi- 
cation, as in Smilax horrida ; when it is called a cirrhus pe- 
duncularis. At other times it passes, in the form of midrib, 
beyond the apex of a single leaf, twisting and carrying witl 
it a portion of the parenchyma, as in Gloriosa superba ; when 
it is said to be a cirrhus foliaris. De Candolle also refers to 
tendrils the acuminate, or rather caudate, divisions of the 
corolla of Strophanthus, under the name of cirrhus corollaris. 
As another modification of the petiole, I am disposed to 
consider with Link (Elem. 202.) the singular form of leaf in 
Sarracenia and Nepenthes (Ji^, 58.), which has been called 
a pitcher (Ascidium, Vasculum outre De Candolle). This con- 
sists of a fistular green body, occupying the place and per- 
forming the functions of a leaf, and closed at its extremity by 
58 
