28 



INDEX 



References are to pages 



Osmosis, continued 



in root hairs 269 



in sponges 58 



Outer coat of pollen grain . 299 



Outer ear (fig.) 217, 218 



Outer skeleton, of crayfish . . 88 



of turtle 130 



Ovary, of coelenterates ... 68 



of frog 118 



part of pistil 297 



Overwork, predisposes to tu- 

 berculosis 240 



Oviducts, of frog 118 



of horned toad 131 



Ovules, change to seed . . . 300 



described 297 



of pine 379 



Owl, feet and beak of ... . 137 



screech (fig.) 138 



snowy, a winter visitant . . . 141 



Oxidation, defined 1, 9 



in birds 138 



Oxygen, a chemical element . 8 

 a condition for the growth of 



bacteria 344 



proportion of, in living things 8 



use in respiration 3 



use of, by birds 138 



Oysters, artificial raising of . 100 

 barnacles and clams growing 



on (fig.) 101 



destroyed by starfish .... 74 



examples of mollusks .... 94 



stages in life history of (fig.) . 101 



value of, as food 178 



Pain 213, 215, 232 



Palate of man 166 



Palisade cells of leaf .... 272 

 Panama Canal, a health prob- 

 lem 239 



Pancreas 169, 172 



Pancreatic juice, enzymes in . 172 



Pansy, capsule of 310 



cleistogamous flower .... 302 

 Paper, made from spruce trees . 384 



Papillae of tongue 165 



Pappus, use of 389 



Paraffin, in transpiration ex- 

 periment 295 



Parallel venation, of corn leaf 282 

 of leaves of lily family . . . 326 

 of grass leaves 323 



Paramoecium 6 



diagram of (fig.) 50 



example of ciliata 6 



mode of defense 51 



reproducing by fission (fig.) . 51 

 resisting attack (fig.) .... 51 

 study of 50 



Parasites, action of 233 



group of fungi 354 



ichneumons 30 



liver fluke 77 



plants, modifications of . . . 389 



tapeworms 76 



Thalessa 39 



Parasitism, a dependent rela- 

 tion 403 



Parsley family, characteristics 



of 331 



list of plants in ..... . 329 



Parsnips, member of parsley 



family 



storage of food in 



Partridge, wings of .... 



Passer domesticus, scientific 

 name of English sparrow . . 



Pasteur, discoverer of lactic 



acid bacteria 



study of bacteria by ... . 



Pasteurization, denned . . . 



Pasteurized milk tested for 

 bacteria 



Pasteur solution, formula of . 



Patent medicines, defined . . 

 to be avoided in consumption . 



Patrolling of forests .... 



Paupers, cost of supporting . . 



Pea plant, modified leaves of 



(fig.) 



member of bean family . . . 



seedlings of 



Peaches produced by rose 



family 329 



Peach-tree borer 28 



Peanut, peculiar habit of (fig.) . 318 

 Peanut shucks as adulterant 180 



329 

 283 

 136 



348 

 350 

 349 



347 

 356 

 244 



237 

 387 

 258 



294 



317 



282 



