184 THE MEDALS OF CREATION. Cyap. VI. 
are parallel, and the interspaces plaited like the folds of a 
fan. The surface of the stem is scored by transverse scars 
formed by the separation of the petioles, and these mar kings 
assist in the identification of the fossil trunks of palm-trees. 
The fruit is in some kinds a single drupe, as the Cocoa- nut ; 
in others a cluster of soft pericarps, as the Date. 
The Palm family is divided into upwards of sixty genera, 
comprising more than a thousand species : the greater num- 
ber are inhabitants of tropical countries. Stems, with the 
external surface and internal structure preserved, and the 
foliage, and fruit, of several kinds of Palms, have been found 
in a fossil state, and chiefly in the Tertiary formations. Ex- 
amples of the large silicified palm-stems from the West India 
Islands, where they occur imbedded with corals petrified in 
the same manner, are to be seen in the British Museum,* 
and most public collections: and sliced polished sections, 
exhibiting the monocotyledonous structure, are common in 
private cabinets. The endogenous organization of the stems 
is So obvious as to leave no doubt as to the class to which the 
trees belong, but M. Brongniart states, that, in the absence 
of the foliage and fruit, it is seldom possible to pronounce 
with certainty that a fossil monocotyledonous stem belongs 
to a Palm; for the internal structure alone does not enable 
the Hopanict to fix upon any characters which will distinguish 
the stems of Palms from those of Pandanus, Agave, Yucca, 
Aloes, Draczena, &c. Fossil monocotyledons known by their 
stems only, are therefore arranged by M. Brongniart under 
the general name of Hndogenites. 
The Palmacites carbonigenus of Corda, and other supposed 
palm-trees of the Coal formation, are regarded by the same 
eminent botanist as essentially differing in structure from 
this family, and belonging to an extinct tribe of exogens. 
That a large proportion of the exogenous stems found in 
* Petrifactions, p. 52. 
awe. 
al Se wry 
