Studies in Animal Life.
"Authentic tidings of invisible things;
Of ebb and flow, and ever-during power,
And central peace subsisting at the heart
Of endless agitation."—The Excursion.
CHAPTER III.
A garden wall, and its traces of past life—Not a breath perishes—A bit of dry moss
and its inhabitants—The "Wheel-bearers"—Resuscitation of Rotifers: drowned
into life—Current belief that animals can be revived after complete desiccation—Experiments
contradicting the belief—Spallanzani's testimony—Value of biology
as a means of culture—Classification of animals: the five great types—Criticism of
Cuvier's arrangement.
Pleasant, both to eye and mind, is an old garden wall, dark with age,
gray with lichens, green with mosses of beautiful hues and fairy elegance
of form: a wall shutting in some sequestered home, far from "the din of
murmurous cities vast:" a home where, as we fondly, foolishly think,
Life must needs throb placidly, and all its tragedies and pettinesses be
unknown. As we pass alongside this wall, the sight of the overhanging
branches suggests an image of some charming nook; or our thoughts
wander about the wall itself, calling up the years during which it has
been warmed by the sun, chilled by the night airs and the dews, and
dashed against by the wild winds of March: all of which have made it
quite another wall from what it was when the trowel first settled its
bricks. The old wall has a past, a life, a story; as Wordsworth finely
says of the mountain, it is "familiar with forgotten years." Not only
are there obvious traces of age in the crumbling mortar and the battered
brick, but there are traces, not obvious, except to the inner eye, left by
every ray of light, every raindrop, every gust. Nothing perishes. In
the wondrous metamorphosis momently going on everywhere in the
universe, there is change, but no loss.
Lest you should imagine this to be poetry, and not science, I will touch on the evidence that every beam of light, or every breath of air, which falls upon an object, permanently affects it. In photography we see the effect of light very strikingly exhibited; but perhaps you will object that this proves nothing more than that light acts upon an iodized surface. Yet in truth light acts upon, and more or less alters, the structure of every object on which it falls. Nor is this all. If a wafer be laid on a surface of polished metal, which is then breathed upon, and if, when the moisture of the breath has evaporated, the wafer be shaken off, we shall find that the whole polished surface is not as it was before, although our senses can detect no difference; for if we breathe again upon it, the surface will be moist everywhere except on the spot previously sheltered
