INDEX. 333 



Light, detrimental to the germination of seeds, 9 — its absence con- 

 ducive to the formation of carbonic acid, 9 — conducive to the 

 formation- of roots, 14. 



Light, by its action on the leaves a principal agent in forming secre- 

 tions, 62 — its effect on the colour of leaves, 52 — its agency in 

 changing the secretion of fruits, 74 — its stimulating effects, 116 

 —its effect in altering and decomposing the fluids of plants, 115 

 —an abundance of, with low temperature, tends to inspissate 

 the sap, 325 — solar, its influence on vegetable life, 41 — effects a 

 decomposition of carbonic acid in plants, 41— occasions the ex- 

 trication of nitrogen in plants, 41 — promotes insensible perspi- 

 ration in plants, 41, 48 — its full intensity can be safely borne by 

 some species but not by others, 53 — more necessary than change 

 of air in imparting flavour to fruits, 152. 



Lights of fruiting-houses, their removal, 156. 



Lignification depends on the action of leaves, 23 — sedimentary mat- 

 ter of, 265. 



lime, applied for' the germination of seeds, 166 — enters into the 

 organisation of plants, 336. 



Liquid manure, 340. 



M. 



Male flowers in unisexual plants, 82. 



Manures, 836 — their application, 340 — principles of their constitu- 

 tion, 839 — their action, 340 — time of their application, 341— 

 manner of their application, 342 — liquid, 340. 



Marsh plants, 114. 



Maturation of fruit, 69. 



Medullary rays, 27. 



Melons, preservation of the purity of their races, 303 — effects of their 

 roots being immersed in water, 116. 



Metallic substances in plants, 335, 336. 



Metamorphoses of the parts of plants, 67 — example of, 57, 61, 178. 



Mildew, 51, 123 — in wheat, attributed to a superabundant absorption 

 of moisture, 51. 



Mineral substances in plants, 836. 



Moisture, atmospheric, when amounting to saturation, occasions a 

 cessation of perspiration in plants, 48 — its absorption by leaves, 

 CI— connected with temperature, 126 — its range, 127 — its mean 



