laboratory of Nature's mysteries out of rain, sunlight, dews, and
earth. On this spot, in this tree, a metamorphosis has so deftly taken
place that it has failed to excite even the wonder of the majority of
men.

[Illustration]

Here, sixty years ago, a school boy planted an acorn. Spring came,
then the germ of this oak began to attract the moisture of the soil.
The shell of the acorn was then broken open by the internal growth of
the embryo oak. It sent downward a rootlet to get soil and water, and
upward it shot a stem to which the first pair of leaves was attached.
These leaves are thick and fleshy. They constitute the greater bulk of
the acorn. They are the first care-takers of the young oak. Once out
of the earth and in the sunlight they expand, assume a finer texture,
and begin their usefulness as nursing leaves, "folia nutrientia." They
contain a store of starch elaborated in the parent oak which bore the
acorn.

In tree infancy the nursing leaves take oxygen from the air, and
through its influence the starch in the nursing leaves is transmuted
into a tree baby-food, called dextrine, which is conveyed by the water
absorbed during germination to the young rootlet and to the gemmule
and also to the first aerial leaf. So fed, this leaf expands, and
remains on the stem all summer. The nursing leaves die when the aerial
leaves have taken their food away, and then the first stage of oak
hood has begun. It has subterranean and superterranean organs, the
former finding plant-food in the earth, and the latter gathering it in
the air, the sunlight, and the storm. The rootlets in the dark depths
of soil, the foliage in the sunlit air, begin now their common joint