22 HOW PLANTS GROW fROM THE SEED. 
Pea (Fig. 42), and of all such plants, is dicotylédonous, that is, has a pair of 
eotyledons, or sced-leaves, which is what the word means. Therefore al! such 
plants are called DicoTYLEDONOUS PLANTS. 
49, Pine-trees, and plants like them, generally have more than’ 
two cotyledons, in a circle; so their embryo is said to be poly- 
cotylédonous ; meaning “ with several or many cotyledons.” Fig. 
49 is a magnified view of a Pine-seed, divided lengthwise, and 
showing the long and straight embryo lying in the middle of the 
albumen. The slender lower part is the radicle or stemlet; the 
upper part is a cluster of cotyledons or seed-leaves, in a close 
bundle; three of them can be seen as it lies, and there are as 
many more behind. Fig. 50 is this embryo as it comes up from 
the seed, its cotyledons (six in number) expanding at once into 
a circle of slender, néedle-shaped leaves. 
50. It is a pity these three words are so long; for the pupil 
should fix them thoroughly in his memory; because these differ- 
ences in the embryo, or plantlet in the seed, run through the whole 
life of the plant, ‘and show themselves in many other differences 
which very strikingly distinguish one class of plants from another. Let it be re- 
membered, therefore, that 
Monocotyledonous Plants, or Monocotyledons,.are those which have only. one 
cotyledon or seed-leaf to their embryo. 
. Dicotyledonous Plants, or Dicotyledons, are those which have a pair of cotyledons 
or seed-leaves to their embryo. 
Polycotyledonous Plants, or Polycotyledons, are those which have more than one 
pair of cotyledons or seed-leaves to their embryo. 
Analysis of the Section. 
24. Flowers produce Fruit; this, the Seed; of this the essential part is the Embryo which grows. 
26. It is alive; but lies dormant awhile. How long seeds may live. 
26. Germination, the beginning of growth; what is needful for it. 27. ied takes place, illustrated 
from the Morning-Glory. 28. How the stemlet grows by lengthening, and carries up the seed-leaves: 
how the root is formed and grows downwards. 29. Instinct of each part to turn in its proper direc- 
tiov# and why. 30. The little seedling a complete plant in miniature; its parts. 31. How it goes on 
to grow: growth of the root; rootlets; of the stem. The Plumule or Bud. Development of the stem 
piece by piece, each with its leaf. 
82. How the seedling is nourished at the beginning. Growth requires food. 88. How this is sup- 
plied by a deposit in the seed; Albumen. 984. It is kept in a solid fgrm until the embryo starts, and is 
