544 PRIMARY FACTORS OF ORGANIC EVOLUTION. 



Pike, 21. 



Pilsbry, 260. 



Pinnotheres holothuriae, 242. 



Pipilo erytkrophthalmiis, 52. 



Pisces, 87, 95, 98, 192, 195. 



Plagiaulacidae, 324, 345. 



Flagiaulax, 142. 



Plant variation, 23. 



Plants, fossil, 77; evolution of, 515. 



Platidia, 178, 179. 



Platypus, 135. 



Plectognathi, 106, 107, 108. 



Plectospondyli, 106, 



Plesiosauria, 114, 121. 



Pleuracanthus, 372. 



Pleuronectidae, 238. 



Plicatula, 267. 



Pliny, 227. 



Pliocene, 387. 



Plistocene, 149, 168. 



Podopterygia, 100. 



PoSbotheriidae, 302. 



Pollard, 89. 



Polygamy, 390. 



Polymastodon, 142. 



Polymastodontidae, 324. 



Polynesians, 154. 



Polypedates, 68 ; P. quadrilineatus 

 D. & B., 68. 



Polyprotodontia, 140, 143. 



Polypterus, 89. 



Polyzoa, 202. 



Porifera, 80, 81. 



Pouchet, 498. 



Poulton, E. B,, 230, 237, 381, 392, 393, 

 439. 449> 461. 



Pre-Carboniferous age, 421. 



Pressure, 286, 292, 295, 340, 405, 519. 



Principle of improvement, 527. 



Proal mastication, 318. 



Proboscidia, 128, 132, i33ti36, 141,144, 

 297. 305. 3061 309. 318, 321, 329, 330, 

 331. 332. 345> 360. 382, 519. 



Procolophonina, 87, 88. 



Procyonidae, 48. 



Production of colors in lepidopterous 

 pupae, 230. 



Prognathism, 417. 



Froportions of limbs and of their seg- 

 ments, 305. 



Prorastomus, 330. 



Protective colors, 392. 

 Proteida, 109, no, in. 

 Proteles, 146. 

 Proterotherium, 359. 

 Proterotome mastication, 318. 

 Proteus, 242. 

 Prothallium, 455. 

 Prothippus, 149, 359. 

 Protodonta, 388. 

 Protophyta, 75, 76, 77, 172. 

 Protoplasm, composition of, 483, 

 Prototheria, 88, 324, 360, 374. 

 Protozoa, 75, 79, 81, 83, 172, 219, 249, 



252, 505. 

 ProtozoSn, 459. 

 Psalidodect mastication, 318. 

 Pseudis, 71. 

 Pseudosauria, 109. 

 Pseudosuchia, 116. 

 Psittacotherium, 329* 346» 351- 

 Ptenophus garrulus Smith, 73. 

 Pteridophyta, 77, 79. 

 Pterosauria, 115. 

 Ptilodus, 324. 



Puerco, 139, 140, 141, 147, 150, 156, 403. 

 Putorius erntineusy 50. 

 Pygopodidae, 123. 

 Pythonomorpha, 120. 

 Pyxicephalus, 71. 



Quadrumana, 132, 133. 1361 i43. 293i 



294, 306, 326, 332, 360, 361, 467. 

 Quebec group, 413, 420. 

 Quenstedt, 189. 

 Quiscalus purpureus^ 52. 



Rabl RQckard, 94. 



Raccoon pacing, 299. 



Rachitomi, 109, no, iii, 372. 



Radiant energy, 484. 



Rana agilis Thomas, 68 ; R. caiesbey- 



ana, 68 ; R. chrysoprasina, 68 ; R. 



claniata, 68 ; R. hexadaciyla, 68 ; R. 



tevtporaria, 64. 

 Ranidae, 65, 70, 71, 389. 

 Raphanus raphanistruni L., 227; R. 



sativus L., 227. 

 Recapitulation, 453, 492. 

 Reduction of digits, 309. 

 Regeneration, 455. 

 Reptiles, degeneracy of the eye of 



