Page:An introduction to physiological and systematical botany (1st edition).djvu/90

 60 above the leaf-buds; that is, in the part of the cutting which, if planted in its natural position, would have been below them. It appears, however, that the sap-vessels must absorb and transmit their sap in a direction contrary to what is natural; and it is highly probable, that after some revolving seasons new returning vessels would be formed in that part of the stem which is now below the buds. I presume there can be no doubt that successive new branches would deposit their wood in the usual position. It is nevertheless by no means common for such inverted cuttings to succeed at all. An experiment to a similar purpose is recorded by Dr. Hales, Vegetable Staticks, p. 132, t. 11, of engrafting together three trees standing in a row, and then cutting off the communication between the central one and the earth, so that it became suspended in the air, and was nourished merely through its lateral branches. The same experiment was successfully practised by the late Dr. Hope at Edinburgh upon three Willows, and in the years 1781, 2, and 3, I repeatedly witnessed their health and vigour. It was observed that the central tree was several days later in coming