ight to form this green, or chlorophyll as it is called. The
chlorophyll-saturated cells, absorbing carbonic acid and the
water-diluted food from the soil, literally break them up. And when
broken, food is found suitable for plants to absorb. Wonderful, is it
not?

"I spoke of carbonic acid; well, this is a gas, as some of you have
found out before, made up of carbon and oxygen. It is a gas which we of
the animal kingdom breathe out as waste from our bodies. The plant takes
it in through the leaf--and, by the way, I ought to explain that. It is
this way: if we had a magnifying glass we should find over the inner
surface of leaves, pores, or stomata as they are called. They open in
the presence of light; and from these openings what the plant has no use
for passes out, and gases from the air may pass in. Some call these
openings breathing pores.

"Quantities of water pass out through these pores. When this process
goes on too rapidly a plant will wilt.

"So, to go back, we will suppose that carbonic acid gas has passed into
the leaves. Straightway the chlorophyll bodies get to work. The gas is
broken up, and oxygen and carbon are left. The carbon is wood the plant
builds. Some of the oxygen passes out into the air and some is kept for
plant food use.

"It is a good thing for us that some of the oxygen does escape into the
air for we need it. So you see we, in our respiration, and the plant, in
its breathing, are doing each other a good turn.

"Of course, there is the dilute food from the soil, which is largely
mineral matter and water. The chlorophyll bodies work away on these
minerals, and make them into foods. A great body of water, as I have
said before, passes out of the plant through the stomata.

"I have told you a thing that the plant can do which we are not capable
of doing. A plant takes a mineral and makes it over into food. You and
I, unless we happen to be circus glass-eaters, are not built to do this
work. But the vegetables which we eat do the work for us.

"A great deal of plant food is in the form of sugars and starches. I
remember Katharine and Peter told me last winter that in their
physiology they learned how sugars and starches were made in our own
bodies. And lo and behold, the geranium can do a similar thing.

"Some plants store up lots of starch, as the potato. Others store
quantities of sugar, as the Southern sugar cane and the beet. Wonderful?
Well, I guess it is. If we could hear and se