viii INTRODUCTORY LESSONS. 
be much easier to make out the exact shapes and positions of the em- 
bryos in most albuminous seeds after they have begun to grow. 
Monocotyledonous Embryos, Corn, wheat, oats, and possibly a 
few other seeds.in your collection, are different in plan from any yet 
described. In corn the soft portion called the chit isthe embryo. Wheat 
and oats have smaller but similar embryos. You cannot easily distin- 
guish the parts of these embryos, but you can, at least, determine that 
they have noé two cotyledons. Really they have one cotyledon, and are 
therefore said to be Jfonocotyledonous. When you study the growing 
seeds you will see how widely they differ from seeds which have— 
Dicotyledonous Embryos. These are embryos, which, like the bean, 
have two cotyledons. A few plants belonging to the Pine Family have 
Polycotyledonous Embryos, Fig. 12 shows the embryo of the 
common Willow or Digger Pine, which has more than two cotyledons in 
a whorl at the top of the radicle. 
The Germination of Seeds. Plant the remainder of your seeds— 
those of a kind together—in boxes or pots of sand, or any kind of loose 
soil you can get. Keep this little experimental garden in a warm place, 
where it can get a bit of sunshine, and water it daily. At intervals of 
three or four days dig up one of each kind of seed, and, after careful 
examination, make drawings to illustrate the successive stages of growth. 
It is of the greatest importance that you repeatedly attempt to draw 
what you see; it is of the least importance that your drawings are pretty. 
You will learn, among many interesting facts, that most seeds 
are pushed up to the surface of the ground by the growth of the radicle. 
There the seed-coats drop off (except that in seeds without albumen the 
cotyledons are apt to slip out of their coats on the way up); the cotyledons 
spread apart, become longer and broader, and turn green; lastly, the 
plumule becomes a leafy stem. Meanwhile, roots grow from the lower 
end of the radicle. Some cotyledons, like those of the pea, do not ap- 
pear above ground, but send the plumule up. The seeds of Big-root— 
a pest which grows in nearly every field—behave in a remarkable manner. 
The nut-like seeds drop from their prickly pods in June or July, and 
soon become covered with leaves. The rains of November and December 
cause them to sprout, as represented at d. The mimic radicle—really o 
