324: STATE POMOLOaiCAL SOCIETY. 



posed to the influences of the atmosphere still retains life, are questio^ns vrhich 

 have not been definitely answered. It is not easy to say wherein the vitality of any 

 perfectly formed tissue, whether of the wood or baric, consists, since their cells- 

 have no power of enlargement or multiplication, though the thickening of the 

 cell walls by the deposition of substances within the cells and the striking 

 changes in color seem to indicate the presence of a feeble life. The functions 

 of the wood seem to be mainly such as may be performed by dead material. 

 The cellulose which has never been exposed to the air may retain its peculiar 

 affinity for water, which is evidently much greater before than after drying. 

 The cells may serve as reservoirs of starch and other substances which may 

 afterwards be imbibed by the living, growing or ripening tissues. The pith, 

 which is alive in young branches so long as leaves are borne upon their wood, 

 dies, apparently, with them. If growth is a characteristic feature of living, 

 tissue, our trees may with some reason be considered annuals, since all their 

 growth proceeds normally from their winter buds and completely envelopes 

 every portion of the tissues of the roots, stems, and branches previously 

 formed, thus excluding them from the weather and preventing their decay, 

 while using them for a support and a magazine of supplies. However this 

 may be, it is certain that the vitality of trees is concentrated in a remarkable 

 manner upon the surface and the extremities of their roots and branches. 



NATURAL GRAFTING. 



Among the observations made during the past season, not the least inter- 

 esting were those relating to the natural grafting which is frequently to be 

 seen in the forest, and which is particularly noticeable among roots. The al- 

 most incredible manner in which the living surface of the inner bark of 

 woody stems can transform the same elaborated sap into different species of 

 wood and bark, was alluded to last year, and the case mentioned of a possible 

 compound tree, containing a plum root and base, on which grew a stem of 

 apricot, surmounted by a stem of blood peach with red wood, and that 

 by a stem of white peach, and the whole by a stem and branches of almond.. 

 Thus, each kind of wood and bark would be perfectly developed from the 

 same material, just as on the same cow's milk may be fed a child, a calf, a colt, 

 a black pig, a white pig, and a lamb. The specific life of each, and not it& 

 food, determines its form, size, and character. 



A COMPOSITE TREE. 



To show still more impressively the peculiar powers of the wood and bark 

 to conduct the crude and elaborated saps in either direction, and to act either 

 as roots or branches, as circumstances require, we will describe an ex2:)erimeut 

 performed by a French gardener, M. Carillet, at Vincennes, in 1866 and 1867. 

 He selected two dwarf pear trees, grafted on quince roots, which were from 

 four to five feet high. One of them was carefully dug up in April, 1866, and 

 fastened in an inverted position above the other. The leading shoots of the 

 two trees were now flattened on one side with a knife, and the two surfaces 

 firmly bound together in the usual manner of splice grafting. The two shoots 

 grew together, and, in the course of the summer following, a few leaves 

 appeared on the main stem of the inverted pear tree, and also on the main 

 branches of the quince roots, which were entirely in the air, some eight or ten 

 feet from the ground. The next spring scions from four varieties of pears 

 were set upon the four main branches of the quince roots, two of which lived 

 and grew several inches. Meanwhile, the inverted pear tree bore two pears. 



