22 



INDEX 



References are to pages 



Intercellular spaces .... 274 



Interdependence of plants . 361 



Internal gills 122 



lungs 122 



structure of earthworms, labo- 

 ratory study of 82 



Interrelationship of animals 61 



Intestine 168 



Invertebrates 6, 103 



Inverted image 217 



Involuntary muscle cells 



(fig.) 189 



Iodine test for starch . . . 265 



Iris of eye (fig.) 216 



Iron 9 



Irregular corolla of saliva . 304 



Irregular flower of violet . 302 



Irregular flowers, denned . . 302 



Irritability 2 



Ivy, adventitious roots of . . . 404 



aerial roots of (fig.) .... 284 



Jack-in-the-Pulpit, storage of 



food in stem of 285 



Jaw bones of fish 106 



Jaw of man 166 



Jellyfish, example of coelenter- 



ate 6 



belonging to hydra group . . 63 



Jenner, vaccination 251 



Jewelweed, explosive fruit of . 312 

 Jimson weed, member of night- 

 shade family 331 



Juice of mustard family, 



characteristics of . . . . 328 

 Juice of the buttercup, char- 

 acteristics of 328 



Junco (fig.) 144 



at hemp and millet station . 148 



at suet station 148 



Katydids, a family of Orthop- 



tera 20 



Keel of bird's breastbone . . 138 



Keeled sternum of bird . . 138 



Kernel, comparison with bean 



pod 262 



Kidney, section of (fig.) . . . 207 



Kidneys of frog 117 



King bird (fig.) 145 



food of 145 



Kingfisher, nesting habits of . 142 



(fig.) 146 



Koch, discoverer of Bacillus tu- 

 berculosis 235 



of tuberculosis test .... 349 



study of bacteria by ... . 351 



Laboratory experiments 



with leaves .... 275, 295 



Laboratory study, of bacteria 346 



of bean seed 261 



of bread mold 360 



of ferns 373 



of foodstuffs in seeds .... 266 



of grasshopper 13, 16 



of gymnosperms ... . 384 



of leaves for storage .... 404 



of live fish 107 



of moss 366 



of moth and butterflies ... 33 



of pleurococcus 339 



of pollination of flowers . . . 305 



of protozoa 50, 53 



of reptiles 135 



of roots 271, 285, 404 



of seed dispersal 314 



of seeds 263 



of skeleton 188 



of spirogyra 341 



of sponge 59 



of starfish 73 



of stems 404 



of tasting 166 



of twigs 291 



of wood 384 



of worms 81 



of yeast plant 356 



Lacteals 174 



Lactic acid, effect of ... . 348 



Ladybug 26 



eggs of (fig.) 26 



Lady slipper (figs.) . . 303, 397 



