"In Bristol County, Mass., in some cases, after pines have been cut off, oak, maple, and birch have sprung up abundantly."
"In Hancock County, Ill., oaks have been succeeded by hickories."
"In East Hamburgh, Erie County, N.Y., a growth of hemlock, elm, and soft maple, was succeeded by beech, soft maple, and hard maple, but a good deal more of the last named than any other."
This is the general character of the summary given, and if its object were simply to show the fact that these alternations actually took place (one that nobody has disputed in the last half century), his chapter on the "Alternations of Forest Growths," is a scientific success. The information really desired in these cases, was that imparted by Dr. Dwight in his suggestive work of travel, in which all the incidental facts and surrounding circumstances are fully given. It does not appear from any of the foregoing statements, given as a specimen, that there were any neighboring trees sufficiently near to have supplied seed for the new forests taking the place of the old,--manifestly the most important physiological fact connected with the whole inquiry, whether looking to proper forest-management, or to future "schools of forestry," certain to be established in this country, as they have been in most of the leading countries of Europe.
It is, however, stated by Dr. Hough, in his voluminous report, that, "in New England, the pine (without giving its varieties) is often succeeded by the white birch, and, in New Jersey, by the oak; the succession of oak by pine, and the reverse, in the southern states." And it is further stated, without reference to the nature and quality of the different soils, or the absence or presence of neighboring seed-trees, that "poplars and other soft woods are very often found coming up in pine districts that have been ravaged by fire." "We have noticed," he continues, "in Nebraska, ash, elm, and box-elder following cottonwood. In the natural starting of timber in the prairie region of Illinois, where the stopping of fires allowed, we often see a hazel coppice; after a time the cratægus, and finally the oaks, black-walnuts, and other timber. These growths are often quite aggressive on the prairies. In Florida, the black-jack oak usually takes the place of the long-leaf pine." In all these cases, the contiguousness of similar, or dissimilar growths, is not stated.
He nevertheless cites a most important fact respecting the alternations of timber growth, noticed by Sir Alexander Mackenzie, in his overland journey from Montreal to the Arctic Ocean, in 1789, who found, in the vicinity of Slave Lake, that the banks were covered with large quantities of burnt wood lying on the ground, where young poplar trees had sprung up immediately after the destruction of the previous growths by fire. In noticing this fact, the indefatigable English explorer remarks: "It is a very curious and extraordinary circumstance that land covered with spruce, pine, and white birch, when laid waste by fire, should subsequently produce nothing but poplars, where none of that species of tree was previously to be found". But facts of a similar character are too numerous and well-authenticated to be questioned by any intelligent authority. And they all point to but one solution--that of primordial germs quickened into life by the necessary environing conditions. The appearance of a single poplar in the locality named, or even a dozen of them for that matter, might be accounted for on the theory that a bird of passage had dropped them there after the fire; but, under no conceivable circumstances, could the dispersion of the requisite amount of seed to plant an extensive burnt district, along the banks of Slave Lake, have occurred on any other theory than that emphatically set forth, as a physiological fact, in the Bible genesis.
There is manifestly importance enough attaching to this subject to justify a much wider range of observation and inquiry than has yet been made. Pine forests have been cut off in Alabama and Georgia, covering extensive areas, where there was not a single oak tree in a circuit of miles; and yet the oak has promptly made its appearance, in several varieties, over the whole cleared district. And it is entirely safe to say that, had the ground been thoroughly examined, from the surface to ten feet below it, after the pine had been felled, not the first sign of an acorn could have been met with anywhere within the whole area of the clearing, no matter whether it covered ten acres, twenty, or a hundred. The paths of the tornadoes we have referred to conclusively show this. The new-born forests, in these cases, do not come from seed, but from the living, indestructible, vital principles implanted in the earth, before it was specifically commanded to "bring forth," in the language of the Bible genesis. The "materialists," like Professor Bastian, Herbert Spencer, and others, may sneer at this declaration, but let them advance some rational theory to the contrary, to account for these alternations of forest growths, before they lay bare the joints of their scientific armor too confidently to the thrusts of the next new-comer in the field of scientific investigation. Sneers are cheap weapons--the mere side-arms of pretension and frippery--but they never bear so deadly a gibe as when effectually turned on the sneerer.
Professor Moritz Wagner, in his description of Mount Ararat, mentions "a singular phenomenon," to which his guide drew his attention, "in the appearance of several plants on soil lately thrown up by an earthquake, which grew nowhere else on the mountain, and had never been observed in this (that) region before." This writer, thereupon, goes into a disquisition upon the vitality of long-buried seeds, but only to mar the value of his very important observation. The fact that these new plants were rejected by the other soil of the mountain--that not thrown up by the earthquake--is the only other observation of value made by this writer. And the importance of this one observation lies in the apparent, if not conclusive fact, that the conditions of the other soil of the mountain were not favorable for the development of the primordial germs, or vital units, contained in that which was thrown up by the earthquake, a circumstance that most materially strengthens the view we have taken, as all candid and impartial readers will agree.
Mr. Darwin inadvertently makes a very material concession in favor of the theory we have advanced, although unconscious of any such theory, except that so broadly and unqualifiedly put forth by the "panspermists" as to meet with a ready refutation. He is laboring, of course, to strengthen his position that nature eternally works to get rid of her imperfect forms, or to ensure "the survival of the fittest." But while his facts accomplish little in this direction, they establish much in another, as the reader will see. He says: "In Staffordshire, on an estate of a relative, where I had ample means of investigation, there was a large and extremely barren heath, which had never been touched by the hand of man; but several hundred acres of exactly the same nature had been enclosed twenty-five years before, and planted with scotch fir. The change in the native vegetation of the planted part of the heath was most remarkable--more than is generally seen in passing from one quite different soil to another; not only the proportional numbers of the heath plants were wholly changed, but twelve species of plants (not including grasses and sedges) flourished in the plantation which could not be found on the heath." The attempt is here made, by Mr. Darwin, to convey an altogether different meaning to his facts than what they will warrant, even as adroitly handled by him. No heath plants were "wholly changed" in characteristics, but only in proportional numbers; nor did the "twelve new species of plants" make their appearance by virtue of any law of variability or selection of the fittest. The growth of scotch fir had simply changed the conditions of the soil, so that certain varieties of heath growth disappeared for the want of "necessary conditions," and certain varieties of forest growth made their appearance because conditions favored. Similar, if not greater changes, are constantly occurring in hundreds of localities in New England, where choked and worn-out pasture lands are left, untouched by the hand of man, to grow up as best they may into new forests. The open-field plants and shrubs entirely disappear, as the stronger and more aggressive trees, taking root in favoring soils, advance in the struggle for supremacy, while the less hardy and more modest plants--those quietly seeking shelter in the woods--make their appearance, because they find, beneath the shade of the usurping forest, the precise conditions necessary for their more successful growth.
No perishable seeds have been awakened from their "sleep of untold centuries" by these changed conditions of the soil; but nature, everywhere obeying the divine mandate, brings forth her implanted life in all its bountiful diversity of stalk, leaf, bud, bough, blossom, fruit,--not in obedience to man's husbandry alone, but because, as the "vicar of God," she must provide for her benefice. "Let the earth bring forth" is the eternal fiat. Nature forever heeds it, and forever obeys it. "Oh, ye blind guides, who strain at a gnat and swallow a camel, doubt it if ye will." But forget not that nature has her "compunctious visitings," and will rise up in insurrection against you. Nothing in her breast lies dormant for ages, or even for an hour. Her appointed times and seasons forbid it. If the butterfly does not sport in her sunshine to-day, it is because it lies dead in its golden-colored shroud, and can never become a butterfly. In all her profusion and prodigality--flinging her glittering jewels, even in mid-winter, over all her enamored woods, and causing her little fountains to leap up from their crystal beds in delight, that they may be frozen, mid-air, into more sparkling jets--she exhibits no such munificence as in her unsparing prodigality of life. To be prodigal in this was the first command she received, and her great heart constantly throbs to give it expression. And in all this she simply obeys a kindly law which has been implanted in her bosom, and can never be displanted. She has no need of seeds in her cunning laboratory to perpetuate plant-life, and only yields them to man for use, and not abuse. He can utilize them if he will, so that all things of beauty and golden-fruited promise shall be his. In the language of her greatest and most profoundly philosophical poet,--