INDEX 



441 



Photosynthesis, illustrated, 131 ; 

 oxygen and water the waste prod 



ucts of, 132, 134; 

 rapidity of, 134. 

 Physics, defined, 15. 

 Physiology, defined, 12; 



importance of osmosis in, 90. 

 Pine seedlings, 76. 

 Pinna, 153. 

 Pistil, 31. 



Pistillate flower of com, 71. 

 Pitcher plant, 140. 

 Placenta, in ovary, 33; 



in pea pod, 50. 

 Plant, a hving, 23. 

 Plant societies, 146. 

 Plasma, composition of, 344; 



function of, 344. 

 Pleura, 382. 

 Pleurococcus, 177; 



formation of zoospores, 177. 

 Plumule, 67. 

 Pocket garden, 82. 

 Pod, study of, 50. 

 Polar limit of trees, 147. 

 PoUen, 31, 32; 

 amount of, 43; 

 protection of, 46. 

 Pollen grain, 32 ; 



germination of, 32. 

 Pollen tube, 32. 

 Pollination by bird, 40; 

 by insect, 36, 39, 42, 43; 

 by water, 45; 

 by wind, 43; 

 Darwin on, 35; 

 defined, 35; 

 self, 42. 

 Poly cotyledons, defined, 75; 



embryo of, 75. 

 Polymorphism, 235. 

 Pome, 52. 

 Pork worm, 214. 

 Primates, 316. 



Prismatic layer of shell, 259, 260. 

 Proboscis, 232. 

 Proglottids, 213. 



Protective resemblance, in dead-leaf 

 butterfly, 239. 



Protective rosomblanrr', defined, 231 ; 

 in katydid, 2:U; 



in luna moth, 240; 



in underwing moth, 240; 



in walking stick, 231 

 Proteid formation in plant, 1.33. 

 Proteid.s, in seeds, 67; 



tests for, 22. 

 Prothallus, 154; 



growth of, 154. 

 Protonema, 157. 



Protoj)lastn, chemical composition <jf 

 28; 



defined, 20; 



properties of, 29; 



structure of, 27. 

 Protozoa, and Motazoa, 188; 



habitat of, 184 ; 



relation of, to di.sea^c, 186; 



skeleton building of, 184; 



use of, as food, 184. 

 Pulse, cause of, 354. 

 Pupa, formation of, 234. 

 Ptarmigan, 303, 304. 

 Pteridophytes, 152. 

 Pyloric caeca, 273. 



Rabbit, adaptations in, 308; 



circulation in, 310; 



nervous system of, 310; 



organs of digestion in, 310; 



skeleton of, 309; 



teeth in, 308, 309. 

 Raceme, 47. 

 Radial canal, 198. 

 Radial symmetry, 203. 

 Radiolarian, skeleton of, 183. 

 Rat, 310. 

 Rattlesnake, 288. 

 Ray flower, 48. 

 Red Alga^, 173. 

 Redia, 213. 

 Reduced leaves, 138. 

 Reflex actions, 407, 409. 

 Regeneration in earthworm, 211. 

 Reproduction, a.^exual, 152; 



zygosporic, 101 ; 



sexual, 151. 

 Reptilia, characU-'risiicij of, 287. 



