INDEX, 



A. 



Absorption, force of, in spongelets, 16. 



Acetate of lime, solution of, rejected by roots, 18. 



Air, deterioration of, by plants at night, 327 — introduction of heated, 

 to plant compartments, 1 53 — purification of, by plants, during 

 the day, 328 — of plant-houses, ventilation a means of drying, 163. 



Air passages penetrate plants in all directions, 102, 



Alburnum, 26 — its connexion with the spongelets, 12 — offices per- 

 formed by it, 32 — its importance, 33 — its quantity proportionate 

 to the number of buds, 187. 



Alburnous substance, 187. 



Ammonia employed to promote germination, 166. 



Amylaceous substance, 188. 



Annuals, oleraceous, 114. 



Annual rest of plants, 319. 



Anther, 56. 



Aquatic plants, 1 14 — necessity of maintaining a due degree of tern 

 perature in the water in which they are grown, 109. 



Aqueous matter, necessity of its excess being decomposed in fruits 

 during the process of ripening, 115. 



Aqueous particles in plants, effects of their being frozen, 86. 



Arid regions, 321. 



Atmosphere, temperature of, at various places, 100 — unfavourable 

 state of, a cause of sterility in flowers, 171— dry, produces an 

 inspissated state of the sap, 325. 



Atmospheric dryness, or moisture, extremes of, 132, 133 — averages 

 of, 133 — moisture, 125. 



Axil, 30. 



Axils of leaves, the situation where leaf-buds are formed, 30. 



B. 

 Balloon training, 262. 



Bark, 28 — its production, 26 — its distinct parts, in trees and shrubs, 

 27 — its anatomical relation to leaves, 37— of the root, its offices, 



15* 



