242 
ORGANOGRAPHY. 
BOOK I 
15. Of the Seed. 
172 175 178 184 183 186 
181 179 185 188 
172. Seed of a Garden Bean. 173. The same, after germination has just begun, and the testa is 
thrown off. 174. Fruit of Mirabilis Jalapa, with the embryo commencing the act of ger- 
mination by protruding the radicle. 175. The same, disentangled from the pericarp, and be- 
come a young plant. 176. A section of the seed of Sterculia, with the embryo inverted in the 
midst of albumen. 177. The embryo of Pinus, taken out of the seed, to show its numerous 
cotyledons. 178. The same, after germination has advanced a little. 179. Seed of Oxalis, 
with the revolute elastic epidermis of the testa. 180. Seed of Salsola radiata divided ver- 
tically, and showing theannular dicotyledonous embryo, rolled round the albumen. 181. Em- 
bryo of the same, taken out of the seed. 182. Section of the seed of Cyclamen, showing the 
transverse embryo lying in the midst of albumen. 183. Section of the fruit of a Grass, with 
the lateral embryo at the base. 184. The same, with germination just beginning. 185. The 
same, after germination is completed, and the monocotyledonous embryo become a young plant. 
186. Section of seed of Scirpus, with germination begun ; the solitary cotyledon is retained 
within the testa, the plumule and radicle are growing beyond it. 187. Section of a Grass 
seed germinating ; the plumula is directed upwards like a slender horn ; the cotyledon is at 
its base, adhering to the albumen. 188. Seed of Commelina germinating ; the cauliculus is 
protruded, is emitting radicles from its end, and has pushed aside the lid called embryotega. 
As the fruit is the ovary arrived at maturity, and is there- 
fore subject to the same laws of structure as the latter ; so is 
the seed the ovule in its most perfect and finally organised 
state, and constructed upon exactly the same plan as the ovule. 
But as the fruit, nevertheless, often differs from the ovary in 
the suppression, or addition, or modification of certain portions, 
so is the seed occasionally altered from the precise structure 
of the ovule, in consequence of changes of like nature. 
The seed is a body enclosed in a pericarp, is clothed with 
its own integuments, and contains the rudiment of a future 
plant. It is the point of developement at which vegetation 
stops, and beyond which no increase, in the same direction 
with itself, can take place. In a young state it has already 
been spoken of under the name of ovule; to which I also 
refer for all that relates to the insertion of seeds. 
That side of a seed which is most nearly parallel with the 
