several days. Also let some seeds remain soaking in the water. The few
seeds in bottle A will sprout, while, the larger number in bottle B
will not sprout, or will produce only very short sprouts. Why do not
the seeds sprout easily in the bottle which is more than half full?

To answer this question try the following experiment:

=Experiment.=--Carefully loosen the cork in bottle B (the bottle
containing poorly sprouted seeds), light a match, remove the cork from
the bottle and introduce the lighted match. The match will stop
burning as soon as it is held in the bottle, because there is no fresh
air in the bottle to keep the match burning. Test bottle A in the same
way. What has become of the fresh air that was in the bottles when the
seeds were put in them? The seeds have taken something from it and
have left bad air in its place; they need fresh air to help them
sprout, but they have not sprouted so well in bottle B because there
was not fresh air enough for so many seeds. The seeds in the water do
not sprout because there is not enough air in the water. Now try
another experiment.

[Illustration: FIG. 36.
To show that seeds need water for germination. The beans in bottle _A_
were soaked 2 hours, those in bottle _B_ were soaked 24 hours. They
were then removed from the water and put into dry bottles.]

[Illustration: FIG. 37.
To show that seeds need air for germination. The beans in both bottles
were soaked 24 hours, and then were put into dry bottles Bottle _A_
contained sufficient air to start the few seeds. Bottle _B_ had not
enough. The water in the tumbler _C_ did not contain sufficient air