INDEX 



429 



Pericardium, 319. 



Peristaltic waves, 303. 



Personal hygiene, 261. 



Perspiration, 343. 



Petals, 35. 



Petri dishes, 140. 



Phagocytes, 316. 



Pharynx, 301. 



Phenolphthalein, 80. 



Phosphoric acid, 82. 



Photosynthesis, 92, 93. 



Physiology of mold, 133. 



Pistil, 36. 



Pith, 97. 



Placentae of mammal, 247. 



Plankton, 235. 



Plants, animals depend on, 34 ; 



and animals, mutually helpful, 18 ; 



classification, 176; 



. food for insects, 33 ; 



as food makers, 88 ; 



function of parts, 48 ; 



groups, 174; 



need minerals, 80 ; 



need of nitrogen, 80, 82 ; 



processes, 103; 



reproduction, 173. 

 Plasma, 313. 



Plasmodium malariae, 182, 217. 

 Pleura, 332. 

 Pleurococcus, 166. 

 Plumule, 59. 

 Pneumonia, 336. 

 Pocket garden, 73. 

 Poison, alcohol, 291 ; 



ivy, 128; 



produced by alcohol, 347. 

 Polar bear, 204. 

 PoUen, 36 ; 



germination of, 53, 54. 

 Pollination, 36, 40 ; 



cross and self, 40 ; 



wind, 44. 

 Pond scum, 173. 

 Pons, 352. 

 Porifera, 182. 



Portal circulation, 309, 322. 

 Portions, hundred calorie, 286. 

 Potato beetle, 214. 



Potato beetle, embryo, 103. 

 Premolars, 302. 

 Preservatives, 147. 

 Prevention of dyspepsia, 310 ; 



of molds, 134. 

 Proboscis, 30. 

 Prolegs, 32. 

 Pronuba, 42, 43. 

 Protecting forests, 114. 

 Proteins, 60, 273 ; 



making, 93 ; 



test for, 61. 

 Protoplasm, 50 ; 



what it can do, 52. 

 Protozoa, 172, 182, 205. 

 Protozoan diseases, 221. 

 Pteridophytes, 176. 

 Ptomaines, 144, 147. 

 Ptyalin, 300. 

 Public hygiene, 389. 

 Pulmonary circulation, 320. 

 Pulse, cause, 323. 

 Pupa of milkweed butterfly, 33. 

 Pupil of eye, 360. 

 Pure food laws, 288. 

 Purpose of digestion, 69, 296. 

 Pyloric caeca, 235. 



Quarantine, 27, 390. 



Rabies, 392. 



Races of man, 196. 



Radiolaria, 182. 



Radiolarian skeleton, 182. 



Recessive characters, 258. 



Rectum, 297. 



Red corpuscles, 313, 314. 



Reflex actions, 353. 



Regulation of heat of body, 343. 



Relation, of age to diet, 280 ; 



of alcohol to crime, 371 ; 



of alcohol to heredity, 372 ; 



of alcohol to pauperism, 371 ; 



of animals to man, 17 ; 



of bacteria to free nitrogen, 81 ; 



of bacteria to man, 16 ; 



of biology to society, 18 ; 



of cost of food to diet, 281 ; 



of digestibility to diet, 281 ; 



