12 PRACTICAL COURSE IN BOTANY 
grains of corn; then pour in water till the bottle is full. Tie a piece of 
wire-netting or stout sackcloth over the top to keep the seeds from being 
forced out. Bind both the neck and the body of the bottle tightly with 
strong cords encircling it in both a horizontal and vertical direction, and 
place under water in a moderately warm temperature. Watch for results. 
EXPERIMENT 16, IS THE FORCE EXERTED IN THE LAST EXPERIMENT 
A MERELY MECHANICAL ONE, LIKE THE BURSTING OF A WATER PIPE, OR 
IS IT PHYSIOLOGICAL AND THUS DEPENDENT ON THE FACT THAT THE 
SEEDS ARE ALIVE ?— To answer this question try Exp. 15 with seeds 
that have been killed by heat or by soaking in formalin. 
Practical Questions 
1. Will a pound of pop corn weigh as much after being popped as be- 
fore? (Exp. 10.) 
2. What causes the difference, if there is any? (Exp. 10.) 
. 3. Does the tuft of downy hairs at the tip of wheat and oat grains 
influence their water supply? The spongy covering of black walnuts and 
almonds? The pithy inside layers of pecans and English walnuts? 
(Exps. 12, 13.) 
4. Why will seeds, as a general thing, germinate more readily after 
being soaked? (Exps. 11, 14, 16.) 
Il. TYPES OF SEEDS 
Mareriau. — Dry and soaked grains of corn, wheat, or oats; bean, 
squash, castor bean, and pine seed, or any equivaient specimens showing 
the differences as to number of cotyledons and the presence or absence of 
endosperm. Each student should be provided with several specimens, 
both soaked and dry, of the kind under consideration. Corn, beans, and 
wheat need to be soaked from 12 to 24 hours; squash and pumpkin from 
2 to 5 days, and very hard seeds, like the castor bean and morning-glory, 
from 5 to 10. If such seeds are clipped, before soaking, that is, if a small 
piece of the coat is chipped away from the end opposite the scar, or eye, 
they will soften more quickly. Keep them in a warm place with an even 
temperature till just before they begin to sprout, when the contents become 
softened. Very brittle cotyledons may be softened quickly by boiling 
for a few minutes. 
No appliances are needed beyond the pupil’s individual outfit and some 
of the food tests given in Section I of this chapter.. 
11. Dissection of a grain of corn. — Examine a dry grain 
of corn on both faces. What differences do you notice? 
Sketch the grooved side, labeling the hard, yellowish outer 
