INDEX. 375 



PAGE 



Quercus robur, formation of its albumous tubes and layers . 145 



RADICLE, at first incapable of absorbing coloured infusions . . 117 



at first destitute of albumous tubes . .181 



, experiments relative to its direction . . . . 124 



derives the substance of its increase from the cotyledons, . 127. 131 



increases in length solely by the addition of new parts to its apex 126 



elongates before albumous substances are generated in it . .142 



Red Spider ... . . 215 



, mode of destroying it . 306 



Resinous matter, in different parts of fir-trees . . 136 

 Ringing ... . 130,131.136.221 



, its effect on the vine . . . 123 



, Physiological observations upon its effects .... 246 



Roots, on their origin and formation . . 153 



are generated by the leaves . .153 



. elongate only by the addition of new parts to their points . . 153 



, when alburnum is formed, possess the power of producing buds . .156 



of trees, their diameter less than that of the trunk and branches . .136 



, fibrous, of trees are of perennial duration . . . . .157 



emitted by bulbs . . . . . . . 156 



induced by ringing . . . . . . .154 



readily emitted by inverted portions of trees . . 106 



, effect of their exposure .... .156 



disperse in every direction . . 129 



, less obedient to the law of gravitation than is the radicle . . 129. 158 



, on the causes which influence the direction of their growth . . . 157 



, mode and direction of their growth . . . . .189 



, in the course of their natural dispersion, increase most where they find 



the best nourishment . . . 129. 333 



are not attracted to any particular source of nourishment . . .129 



progress indifferently toward poisons and rich soil . . . 162 



progress in a particular direction in consequence only of external causes 160. 162 



, on facilitating their emission from layers . . . . 1 95 



, their growth and form affected by the motion of the stem . . . 163 



, their natural decay slower than that of branches . . 83, 325 



, fibrous . . . . . . . . 281 



, lateral, cause of their formation , . . . . .129 



Rosa indica ... . . 287 



SACCHARINE matter . . . . . . . .152 



Salix, experiments with cuttings of . . . . . 107 



Sap in trees, its ascent ... 24 



rises wholly through the alburnum .... 93. 109. 131 



, remote cause of its ascent . . . . . . . 91 



of trees, account of some experiments on its ascent . . .84 



