The moulds which cover bread and cheese with a delicate tracery of filaments and raise on high their tiny balls of spores are as worthy to be called a plant growth as are the great oaks which shade our houses. The rusts and mildews and blights which destroy our fruit all have their beauty of growth and fruition when we examine them through a lens, and the yeast by which flour and water is made to rise into the porous, spongy dough is just as truly a plant as is the geranium blossoming at the kitchen window.
If we wonder at the fierce struggle for existence which allows only a few out of the many seeds of a maple or thistle to germinate and grow up, how can we realise the obstacles with which these lowly plants have to contend? A weed in the garden may produce from one to ten thousand seeds, and one of our rarest ferns scatters in a single season over fifty millions spores; while from the larger puff-balls come clouds of unnumbered millions of spores, blowing to the ends of the earth; yet we may search for days without finding one full-grown individual.
All the assemblage of mushrooms and toadstools,--although the most deadly may flaunt bright hues of scarlet and yellow,--yet lack the healthy green of ordinary plants. This is due to the fact that they have become brown parasites or scavengers, and instead of transmuting heat and moisture and the salts of the earth into tissue by means of the pleasant-hued chlorophyll, these sylvan ghosts subsist upon the sap of roots or the tissues of decaying wood. Emancipated from the normal life of the higher plants, even flowers have been denied them and their fruit is but a cloud of brown dust,--each mote a simple cell.
But what of the delicate Indian pipe which gleams out from the darkest aisles of the forest? If we lift up its hanging head we will find a perfect flower, and its secret is discovered. Traitor to its kind, it has dropped from the ranks of the laurels, the heather, and the jolly little wintergreens to the colourless life of a parasite,--hobnobbing with clammy toadstools and slimy lichens. Its common names are all appropriate,--ice-plant, ghost-flower, corpse-plant.
Nevertheless it is a delicately beautiful creation, and we have no right to apply our human standards of ethics to these children of the wild, whose only chance of life is to seize every opportunity,--to make use of each hint of easier existence.