THE SEED. 137° 
stem, growing upwards, and becoming stem and branches, | 
&e. It is often undistinguishable till germination has made 
ome progress, being closely adherent to the cotyledon, as in 
monocotyledonous plants. It is very well seen between 
the cotyledons of the Pea or Bean, in which it is formed of 
Several minute leaves closely folded together. These be- 
come the first or primordial leaves. The gemmule may be 
regarded as the first bud of the new plant, ready to be de- 
eloped when situation and other circumstances are favour- 
able. (See Figs. 56,57.) In Fig. 57, the gemmule and_ 
radicle are represented as they appear after germination — 
has made some progress. 
536. The Radicle (b, Fig. 57.) is the rudiment of the 
root, and is continuous downwards with the gemmule. It is 
ways simple and undivided, and in the dicotyledonous seed 
of a conical shape with the apex inferior. It always points 
wards the micropyle (516), and invariably grows towards 
the centre of the earth, forming the root of the new plant. 
537. Those plants in which the radicle is free and naked, Ss 
t being enclosed in any sheath (excepting, of course, the 
Pisperm) were called exorhize by the late M. Richard, and 
correspond to the exogenous or dicotyledonous plants of 
her authors ; as the Bean, in which the free pointed radi- — 
e is well seen. 
538. Those in which the radicle is enclosed in a sheath 
ere called endorhize by Richard, and correspond to the 
dogenous or monocotyledonous plants of other authors, as 
at. : 
539. In the Conifer and Cycadew the radicle is incor- 
porated in a peculiar manner with the albumen: These were pee oe 
 synorhize by Richard, but are included among the 
‘ogenous plants of other authors. ee 
540. The part between the radicle and gemmule is called 
© collet or neck, and is the point where the ascending and 
ending parts meet ; the root elongating downwards from 
and the stem elongating upwards from the same spot. 
541, The embryo is homotropous or orthotropous wh 
when 
