INDEX. 347 



plants during the day, 42 — its formation by plants during the 

 night, 42 — its digestion and decomposition in the system of 

 plants, 42 — ^period at which leaves cease to decompose it, 53 — ■ 

 conditions under which it is slowly formed, 167 — formation of, 

 in seeds, 180 — decomposed, furnishes an essential part of the 

 secretions of plants, 340. 



Carburetted hydrogen gas, 118. 



Cellular system, 217 — ^horizontal, 282. 



Cellular tissue combined with woody fibre, 24. 



Charcoal, packing seeds in, 181. 



Chemical changes in seeds, 159. 



Cherries, forcing o^ 109. 



Chinese mode of dwarfing trees, 251 



Chlorine employed to promote germination, 167. 



Cicatrisation, 282. 



Circulation of sap, 32. 



Climate, uniform, 319. 



Climates, extreme, 320— extreme, imitation of, 107. 



Climbers, 265. 



Colour of leaves influenced by light, 62 — the natural green in plants, 

 circumstances which prevent its being acquired, 34 — green, in 

 plants, how produced, 84 — ^yellow, in plants, cause of its occui^ 

 rence, 84. 



Colouring matter, green, decomposed by frost, 86. 



Colours of plants, cause of their formation, 84. 



Corrai, 29. 



Corolla, its nature, 65 — its use, 67. 



Cortical integument, 27. 



Cotyledons, 10 — supply nourishment to the plumule, 28. 



Creepers, 265. 



Crops, change of, 270, 338, 833 



Cross-beds 68 — are generally fertile, 68. 



Cross-breeding, 310 — process of, 314. 



Cucumbers, advantage of growing them in forcing-houses, instead of 

 pits, in winter, 155. 



Curl in potatoes, 73. 



Cuttings, propagation by, 195 — conditions required in order to en- 

 able them to become young plants, 196 — double pots employed 

 in striking them, 202. 



