INDEX 



481 



Rhubarb, protection of root of, 162. 

 Ribes. See Currant. 

 Ricinus. See Castor-bean. 

 Riley on food of plant, 344. 

 Rind, function. of, 257. 

 of root, 120,* 121. 

 of stem, 224,* 225,* 232,* 233, 236.* 

 starch in, 258, 

 Ring, annual, 247. 

 bast-226, 246. 

 cambium 246. 

 woody, 226, 246. 

 Ringing, 256, 257, 318. 

 Ripening of fruits, 316. 



- seeds, 314. 



River water, plant-food in, 138. 

 Rivers, self-purification of, 382, 383. 

 Roberts, on fertilizers, 153. 

 Robinia. See Locust. 

 Rocks, decomposition of, 109, 144, 145. 

 Roguing, 451. 

 Rogues, 451. 

 Rolling of leaf protects it against drying, 



213, 334. 

 Root, aeration of, 36, 37,* 38, 39,* 40, 103, 



119,* 120,* 124-126, 128, 130, 132. 

 aerial, 275.* 



absorption of water by, 88, 102, 103, 119,* 

 120,* 121-123 * 



affected by heat, 332. 

 - salts, 124, 336. 

 acid excreted by, 141-143,* 144, 145. 

 anchors plant in soil, 87.* 

 behavior of, to obstacles, 99.* 

 buds formed on, 249. 

 care of, 135, 136. 

 climbing, 275.* 

 contraction of, 87. 

 decomposes rocks, 144, 145. 

 depth of penetration of, 134, 135. 

 direction of growth of, influenced by air, 

 89, 98, 135. 



centrifugal force, 92.93,* 



94. 



food, 89, 98. 



gravity, 88,* 89,* 90, 91,* 



92, 93,* 94, 95, 98,* 99. 



- heat, 89, 98. 



- water, 89, 95,* 96,* 97, 98. 



EE 



Root, effect of heat on, 332. 



water on the form of , 341. 



etches marble and plaster of Paris, 144. 



excretion by, 141-143,* 144, 145. 



exploration of soil by, 133-135. 



food in, 122, 125, 260. 



force of growth of, 81, 82,* 83, 84,* 85. 



fungi on, 150. 



gives off carbonic acid, 141-143,* 144. 



growing region of, 85,* 86. 



microscopic structure of, 120,* 121, 255. 



needs air, 125. 



of water-plants, 339. 



osmotic action of, 123, 124. 



path of water in, 120,* 121. 



penetration of soil by, 80,* 81.* 



propagation by, 433. 



protection of, 161, 162. 



proteids in, 255. 



pruning of, 136, 318. 



regeneration of, 86. 



resemblance of rhizome to, 277. 



selective action of, 161. 



shallow vs. deep, 87. 



storage of food in 260. 



strengthening fibers of, 120,* 267, 268. 



sugar in, 122. 



tip of, how protected, 86. 



result of injury to, 86. 



treatment of, to promote fruit produc- 

 tion, 342. 



tubercles of, 49,* 384, 385. 

 Root cap, 86. 



Root-hairs, absorb water by osmosis, 121 

 123,* 124, 242. 



effect of water on growth of, 102. 



method of obtaining, 100,* 101.* 



of radish, 100,* 101.* 



of Wandering Jew, 102.* 



relation to soil-particles, 119, 120, 121. 



turgidity of, 123. 

 Root-pressure, 243,* 244. 

 Root-stock. See Rhizome. 

 Rosa. See Rose. 

 Rose, calyx of, 288. 



climbing of, 270. 



protection of, against animals, 221. 

 Rose, Moss, origin of, by bud variation, 420 

 Rose, family, cross-pollination of, 303. 



