conditions permitted to human experience. If, then, man shall some day create living matter, he will be able to observe it during a longer or shorter time; he will be able to study it; but it will be an embryo, the development of which can not be completed, on account of the absence of suitable conditions of the medium.—Translated for The Popular Science Monthly from the Revue Scientifique.
| ECONOMICAL TREES. |
By FREDERICK LE ROY SARGENT.
THE well-known power which many plants possess of developing adventitious roots from almost any part, when placed under favoring conditions, is manifested in a somewhat extraordinary manner by several trees recently brought to the notice of botanists.
In the Bulletin of the Torrey Botanical Club for August, 1891, the present writer published an account of a linden growing in Boston, Mass., where it had been subjected to injury from horses gnawing the bark, and in consequence had a considerable portion of the trunk decayed, as shown in the accompanying sketch (Fig. 1). At the edge of the wound the cambium had formed a callus, and from a point in this living tissue there proceeded several vigorous roots which penetrated the decaying wood in all directions, evidently finding a rich soil.
Subsequent issues of the Bulletin have contained descriptions of several other examples of trees exhibiting a similarly economical utilization of the products of their own decay. These include swamp maples, a Norway maple, a willow, and a white mulberry. In an English paper appeared not long ago an account of an oak which had "sustained itself for years by a mass of roots grown into its own trunk!"
In one of the swamp maples observed by L. M. Stabler, at Great Neck, Long Island, the primary injury apparently resulted from a storm which split and twisted the trunk. One of the adventitious roots, "at least two inches in diameter, started as high as ten feet above the base of the trunk, and passed down through the decayed portion to the ground" (Fig. 2).
The Norway maple, described by W. A. Buckhout, had "a large branch split off, showing that the splitting had started several years before, that the margins of the trunk had become well calloused, and from several points roots had extended into the cleft, which naturally became partially filled with dust and decaying bark. The largest root was an inch in diameter, divided considerably near the lower end, and was over two feet long."
