CHAP. II. 
ENDOGENOUS STEMS. 
105 
the life of every thing that increases in diameter; or at least 
produces, above the strangled part, extensive swellings, which 
end in death. 
It is, however, certain that other Endogens do increase 
extensively in diameter up to a certain point ; sometimes this 
is effected with great rapidity ; and the horizontal growth once 
stopped appears never to be renewed : thus, in the Bamboo, 
stems are sometimes found as much as two feet in circum- 
ference, which were originally not more than half an inch in 
diameter. Others would seem to have an unlimited power of 
distension : in the Dracaenas, called in French colonies in 
Africa Bois-chandelles, the first shoot from the ground is a 
turio (sucker), an inch in diameter, and perhaps fifteen feet 
high ; but in time it distends so much that sometimes two men 
can scarcely embrace it in their extended arms. ( Tliouars^ 
Essais, p. 3.) 
As Endogenous stems contain no concentric zones, there is 
nothing in their internal structure to indicate their age ; but 
in the opinion of some botanists, there are sometimes external 
characters which will afford sufficient evidence of it. It is said 
that the number of external rings which indicate the fall of 
leaves from the trunk of the Palm tribe coincides with the 
number of years that the individual has lived. There is, 
however, no proof of this at present ; such statements must 
therefore be received with caution. It may further be re- 
marked, with reference to this subject, that in many Palms 
these rings disappear after a certain number of years. 
In arborescent Endogens it usually happens that only one 
terminal leaf-bud developes ; and in such cases the stem is 
cylindrical, or very nearly so, as in Palms. If two terminal 
leaf-buds constantly develope, the stem becomes dichotomous, 
but the branches are all cylindrical, as in Pandanus and the 
Doom Palms of Egypt ; but if axillary leaf-buds are regularly 
developed, as in the Asparagus, Dracaena Draco, or in arbor- 
escent grasses, then the conical form which prevails in 
Exogens exists in Endogens also. 
In Endogens there are but few important anomalies in 
structure; and of these the most striking, namely that of 
Grasses, is more peculiar than anomalous. Yucca appears. 
