366 INDEX. 



PAGE 



Aphis 215 



Apple subjected to experiment in order to obtain new varieties . . . 175 



, Cornish gilliflower 325 



, Downton pippin 1 75 



Apricot 251 



, Moor-park 222 



, an account of the injurious effect of the plum-stock upon . 272 



Peche 222 



, causes of the premature death of parts of its branches . . 336 



stock 222 



BARK, principal substances of which it is composed 139 



consists of layers $7 



, substances which compose it exist in the cells of both bark and alburnum 143 



reproduced from the alburnum 139 



not generated in all cases from the alburnum 142 



, substance by which it is attached to the alburnum . . . .146 



of trees, on its formation 136 



, its vessels and fibres adhere less firmly to the alburnum than to each 



other 146 



, its vessels traced to the extremities of the roots . . . . . 106 



, effect produced on trees by its removal 118 



reproduced from the surface of the alburnum 137 



, its organization better adapted for transmitting the sap towards the roots 



than otherwise .... 138 



, its capacity for generating new bark 139 



deprived of buds cannot generate alburnum 1 47 



possesses in a slight degree the power of forming wood . . . . 103 



, on its inconvertibility into alburnum 143 



, experiment on its transposition 144 



of trees do not transmit coloured infusions 150 



inner, consequences resulting from its being suddenly affected by cold in 



spring 286 



Barley, retentive of its early habit 1 74 



Baskets employed for preserving the roots of melon plants . . . . 305 



Bean 37 



, experiments with reference to the direction of the growth of roots made 



with it 159 



Bees, on their economy 348, 354 



Berberry-tree supposed to communicate mildew to wheat . . . . 205 



Birch, specific gravity of its sap Ill 



Blossoms and fruit, their production induced in the potatoe . . . . 133 



Blossoms, a cause of their formation 101 



Boletus lacrymans . . . . . . . . . . 204 



squamosus ........... 204 



Bottom-heat for pine plants 302 



