INDEX 



293 



Hotbeds, 159 



Humid regions, 11 



Humus, 30; a source of nitrogen, 



107 ; effect on soil, 39, 43 

 Hybridizing, 262 ; how accomplished, 



263 

 Hybrids, 262 ; method of producing, 



263 



Hydrogen, characteristics of, 8 

 Hydrophytes, 126 ; xerophytic, 127 



Inarching, 194 



Insects, damage to plants from, 245 ; 

 forms that cause injury, 246 ; meta- 

 morphoses of, 245 ; methods of 

 combating, 255 ; poisons for, 252 ; 

 preventing attacks of, 252 ; smoth- 

 ering sprays for, 254 



Insects, helpful : ant lion, 256 ; 

 dragon fly, 256 ; ichneumon fly, 

 256 ; ladybird, 256 ; ladybug, 256 ; 

 spiders, 256 ; tiger beetle, 256 



Insects, injurious: blister beetles, 250; 

 borers, 249 ; cabbage worm, 247 ; 

 cankerwonn, 249; codlin moth, 

 249 ; corn-ear worm, 248 ; cucum- 

 ber beetle, 250 ; curculio, 249 ; cur- 

 rant worm, 248 ; cutworm, 247 ; 

 elm-leaf beetle, 250; May beetle, 

 250 ; mealy bug, 251 ; plant lice, 

 251; potato beetle, 250; scale in- 

 sect, 251 ; squash bug, 251 ; tent 

 caterpillar, 248 ; tomato worm, 247 



Insects, poisons for : arsenate of lead, 

 253 ; Paris green, 252 ; white helle- 

 bore, 252 



Insects, smothers for : carbon disul- 

 phide, 254 ; hydrocyanic gas, 254 ; 

 kerosene emulsion, 254 ; Persian 

 insect powder, 254 ; tobacco smoke, 

 254 ; tobacco water, 254 ; whale- 

 oil soap, 254 



Intercellular spaces, 73 



Iron, characteristics of, 7 ; in plants, 

 99 



Labels, forms of, 143; method of 



writing, 141 

 Lath houses, 123 

 Lawn, care of, 201 ; how to make, 



198; paths in, 199; seeding, 198; 



sodding, 19!) 

 Layering, air, 189 ; forms of, 188 ; 



mound, 189 ; nature of, 188 ; pot, 



189; tip, 188; vine, 188 



Leaf crops, 279 



Leaves, branching, 72 ; epidermis of, 



72 ; fall of, 77 ; structure of, 71, 



73 ; veining of, 72 



Legumes, as food, 280 ; and bacteria, 



108, 110 

 Leucoplasts, 77 

 Life cycle of plants, 87 

 Light, effect of lack of, 122 ; needed 



by plants, 122 ; protection from, 



123 



Lime, effect on soil, 39 

 Lime plants, 7, 99 

 Loam, 34 



Magnesium, characteristics of, 6 ; in 



plants, 99 

 Manganese, characteristics of, 7 ; in 



plants, 100 

 Mantle rock, 12 ; changes in, 22 ; 



turned to soil, 23 

 Manure, derivation of the word, 106 ; 



green, 106 

 Marl, 30 



Medullary rays, 67 

 Mendel's law, 264 ; illustrations of, 



265 



Mesophytes, 127 

 Metals, and nonmetals, 1 ; properties 



of, 2 



Micropyle, 86 

 Molecules, 2 



Monocotyledon flower, plan of, 83 

 Mulch, dust or summer, 152 

 Mulching, 120, 152, 211 

 Mutation theory, 275 

 Mutations, 261 

 Mycorrhizas, 109 ; plants associated 



with, 109 



Nectar guides, 82 



Nitrates, 108 



Nitrification, 106; bacteria concerned 

 in, 107 



Nitrites, 108 



Nitrogen, characteristics of, 8 ; fixa- 

 tion of, 108 ; source of, 105 ; use 

 of, by plants, 98 ; value of, 106 



Nonmetals, examples of, 2 



Nucleus, 58 



Orders, 91 



Osmosis, 63 ; in the plant, 63 



Ovary, 79 



Overwatering, effect of, 124 



