20 



INDEX 



References are to pages 



Hepatica, example of incom- 

 plete flowers 



Heredity, discussed 



of disease 



Hermit crabs, economic impor- 

 tance of 



Herons, beak of 



Herring, economic importance of 

 Herring- gulls (fig.) .... 

 Hibernation, defined .... 



study of 



Hickories, members of walnut 



family 



Hills, a method of planting . . 



Hilum of bean 



Hinge of clam 



Hinge ligament of clam . . . 



effect of starfish on .... 

 Hinge teeth of clam . . . . 



Hip bones of man 



History, of bean plant .... 



of corn plant 



Hogs, fed on beans 



inspection of 



Hollow bones of birds . . . 

 Hollow stem, of horsetail . . 



of parsley family 



Hollyhock, member of mallow 



family 



Home making, work of women 

 Home study of moths and 



butterflies 



Honey, amount of carbohydrate 

 in 



locust, seedlings of (fig.) . . 



made from nectar by bees . . 



value of in U. S 



Honeybee, discussed .... 



stages in development (fig.) 



worker, queen, drone (fig.) . . 



Honeybees clustering at 



swarming time (fig.) . . 



Hoofs of cattle, origin of . . 



Hooks, on fruit of burdock . . 



on seeds, use of 



Hookworm disease .... 

 Hop lice destroyed by lady- 

 bugs 



Hops, use of, in manufacturing 

 of beer 



302 

 125 

 255 



91 

 137 



106 

 137 

 115 

 159 



327 



402 



260 



96 



96 



73 



96 



187 



317 



320 



316 



243 



138 



374 



331 



329 

 257 



33 



170 

 281 

 297 

 39 

 34 

 35 

 34 



36 

 190 

 313 

 389 

 239 



26 



355 



Horehound, a medicine . . . 331 



Horned pout (fig.) 105 



Horned toad, a lizard (fig.) 129, 131 



Horns of cattle, origin of . . 190 



Horse, classified 7 



discussed 153 



evolution of 154 



use of 155 



Horse-chestnut, compound 



leaves of 294 



seedlings (fig.) 281 



twig of (fig.) 288 



woody stem 287 



Horse-radish, member of mus- 

 tard family 328 



Horsetail (fig.) 374 



joints of stem 374 



Horsetails, members of fern 



group 373 



related to ferns 369 



Host, defined ....... 31 



of liver fluke 77 



Hot air heating (fig.) . . . 195, 196 



House flies, eaten by birds . . 145 



Housefly (fig.) 41 



bacterial growths from (fig.) . 250 



bacteria and mold from (fig.) . 251 

 House sparrow, scientific 



name for 7 



Houses, source of materials for 401 



Human biology 161 



Human stomach, X-ray photo- 



• graph of (fig.) 168 



Humming birds, beak of . . 137 



summer residents 141 



Humor, aqueous 216 



vitreous 216 



Humus destroyed by fires . 387 



Hydathodes, defined .... 274 



Hydra, cell layers in (fig.) . . 65 



diagram of (fig.) 64 



example of coelenterate ... 6 



laboratory study of ... . 66 



microphotographs of (fig.) . . 63 

 microphotographs of body wall 



of ... 64 



Hydra-like animals described 63 



summary of 70 



Hydras, examples of coelente- 



rates 63 



