374 INDEX. 



PAGE 



Pit, description of one for melons and pine-apples . . . '261 



Plants possess no degree of sensation . . . . . .163 



possess not a locomotive organisation, therefore the endowment of sen- 

 sation useless . . . . . . . 164 



Pistillum, the termination of the medulla . . . . .88 



Plants adapt, to a certain extent, their habits to the circumstances in which they 



are placed ......... 173 



in pots, compost for certain kinds of ..... 256 



Plumule . . . . . . . . . . 189 



affected by gravitation . . - . . .167 



Plum-stock ......... 272 



, height attained in one season by a seedling . . . 211 



Pollen, remarks on its supposed influence in cross-breeding, upon the colour of 



the seed-coats of plants, and the quality of their fruits . . - 278 



Potato, formation of buds within its substance . . .120 



- consists of four.distinct parts . . . . 104. 120 

 -, experiments with the . . . . .133. 134 



, the component matter of its tubers previously exists either in the stem 

 or leaves ........ 134 



made to produce tubers on the stem . . . .156 



, its runners similar in organization to the stem . . .157 



, tubers not obtained from its fibrous roots . . . . 156 



, experiments with its leaves . . . . . . . 169 



, its tubers increased by destroying the fructification . ..183. 320 



, a communication on the ...... 183 



- , remarks on the disease of curl in the . . . . 185 



, on the prevention of curl in the . . . . . 197 



, sets taken from the crown produce diseased plants . . . 198 



, account of an improved method of raising early crops of the, in the 



open ground ........ 256 



, on its culture . ...... 300.318.334 



, an account of an economical method of obtaining very early crops of . 310 



affords wholesome nourishment . . . . .319 



, mode of raising it from seed . . . . . 322 



, advantage of planting large tubers ... . 257,331 



, great produce obtained per acre . . . . . . 335 



, Lankman's . .... 300. 322. 334 



Propagation of trees by cuttings in summer . . . . 340 



Pruning of the peach-tree . . . . . . 226 



of the pear-tree ....... 203 



of standard trees ... ... 233 



of timber trees ... ... 141 



Prunus ... ..... 251 



Pseudo-Cerasus, upon its culture . . . . . . 295 



QUINCE-STOCK ........ 222. 272 



