CHAPTER XI
NATURE UNDER GLASS
The next morning Amy asked Mrs. Clifford to initiate her more fully into the mysteries of her flowers, promising under her direction to assume their care in part. The old lady welcomed her assistance cordially, and said, "You could not take your lesson on a more auspicious occasion, for Webb has promised to aid me in giving my pets a bath to-day, and he can explain many things better than I can."
Webb certainly did not appear averse to the arrangement, and all three were soon busy in the flower-room. "You see," resumed Mrs. Clifford, "I use the old-fashioned yellow pots. I long ago gave up all the glazed, ornamental affairs with which novices are tempted, learning from experience that they are a delusion and a snare. Webb has since made it clear to me that the roots need a circulation of air and a free exhalation of moisture as truly as the leaves, and that since glazed pots do not permit this, they should never be employed. After all, there is nothing neater than these common yellow porous pots. I always select the yellowest ones, for they are the most porous. Those that are red are hard-baked, and are almost as bad as the glazed abominations, which once cost me some of my choice favorites."
"I agree with you. The glazed pots are too artificial to be associated with flowers. They suggest veneer, and I don't like veneer," Amy replied. Then she asked Webb: "Are you ready for a fire of questions? Any one with your ability should be able to talk and work at the same time."
"Yes; and I did not require that little diplomatic pat on the back."
"I'll be as direct and severe as an inquisitor, then. Why do you syringe and wash the foliage of the plants? Why will not simple watering of the earth in the pots answer?"
"We wash the foliage in order that the plants may breathe and digest their food."
"How lucid!" said Amy, with laughing irony. "Then," she added, "please take nothing for granted except my ignorance in these matters. I don't know anything about plants except in the most general way."
"Give me time, and I think I can make some things clear. A plant breathes as truly as you do, only unlike yourself it has indefinite thousands of mouths. There is one leaf on which there are over one hundred and fifty thousand. They are called stomata, or breathing-pores, and are on both sides of the leaf in most plants, but usually are in far greater abundance on the lower side. The plant draws its food from the air and soil—from the latter in liquid form—and this substance must be concentrated and assimilated. These little pores introduce the vital atmosphere through the air-passages of the plant, which correspond in a certain sense to the throat and lungs of an animal. You would be sadly off if you couldn't breathe; these plants would fare no better. Therefore we must do artificially what the rain does out-of-doors—wash away the accumulated dust, so that respiration may be unimpeded. Moreover, these little pores, which are shaped like the semi-elliptical springs of a carriage, are self-acting valves. A plant exhales a great deal of moisture in invisible vapor. A sunflower has been known to give off three pounds of water in twenty-four hours. This does no harm, unless the moisture escapes faster than it rises from the roots, in which case the plant wilts, and may even die. In such emergencies these little stomata, or mouths, shut up partly or completely, and so do much to check the exhalation. When moisture is given to the roots, these mouths open again, and if our eyes were fine enough we should see the vapor passing out."