BOOK II. 
GENERAL CONSIDERATIONS. 
285 
their diameter increasing by addition to the inside. As the 
seeds of such plants are formed with only one cotyledon, they 
are called monocotyledonous ; and their growth being from 
the inside, they are also named endogens. In these plants the 
functions of the leaves, flowers, and fruit are in nowise dif- 
ferent from those of the apple; their peculiarity consisting 
only in the mode of forming their stems. When a monocoty- 
ledonous seed has vegetated, it usually does not disentangle 
its cotyledon from the testa, but simply protrudes the collum 
and the radicle ; the cotyledon swelling, and remaining firmly 
encased in the seminal integuments. The radicle shoots 
downwards to become root ; and a leaf is emitted from the 
side of the collum. This first leaf is succeeded by another 
half-facing it, and arising from its axil ; the second produces 
a third half-facing it, and arising also from its axil ; and, in 
this manner, the spiral production of leaves continues, until 
the plant, if caulescent, is ready to produce its stem. Up to 
this period, no stem having been formed, it has necessarily 
happened that the bases of the leaves hitherto produced have 
been all upon nearly the same plane: and, as each has been pro- 
duced from the bosom of the other without any such interven- 
ing space as occurs in dicotyledonous plants, it would be im- 
possible for the matter of wood, if any were formed, to be sent 
downwards around the circumference of the plant ; it would, 
on the contrary, have been necessarily deposited in the centre. 
In point of fact, however, no deposit of wood like that of 
dicotyledons takes place, either now or hereafter. The union 
of the bases of the leaves has formed a fleshy stock, cormus, 
ov plate^ which, if examined, will be found to consist of a mass 
of cellular tissue, traversed by perpendicular and horizontal 
bundles of vascular and woody tissue, taking their origin in 
the veins of the leaves, of which they are manifest prolonga- 
tions downwards; and there is no trace of separable bark, 
medullary rays, or central pith : the whole body being a mass 
of pith, woody and vascular tissue, mixed together. To 
understand this formation yet more clearly, consider for a 
moment the internal structure of the petiole of a dicotyledon : 
it is composed of a bundle or bundles of vascular tissue 
encased in pleurenchyma, surrounded on all sides with pith. 
