Index. 



Protozoa, 104. 

 Ptarmigan, 317, 318. 

 Pterodactyl, wing of, 56. 

 Purpose, Darwin's use of the word, 



281, 340. 



Puss moth, larva of, 325, 326. 

 Python, 66, 67. 



Q. 



Quadrumana, muscles of, 76, 8 2, 83; 

 perforations of humeri of. 94, 

 95 ; hair on phalanges of, 91. 



R. 



Rabbit, embryology of, 153 ; mul- 

 tiplication of, in Australia, 286 ; 

 portraits of wild and domesticated 

 breeds of, 308 ; protective colour- 

 ing of, 319, 320. 



Radiate form, beauty of, 408, 409. 



Raia radiata, and batis, 367 371. 



Rats, species of, restricted to Old 

 and New Worlds, 212; British 

 and Norwegian, 285, 286. 



Rattle-snake, tail of, 289. 



Recognition marks, 271-273. 



Religion, in relation to Darwinism, 

 401-418. 



Reproduction, different methods of, 

 106-117 5 essence of sexual, no; 

 foreshadowing of sexual in uni- 

 cellular organisms, 1 1 5-1 1 7. 



Reptiles, wing of flying 56 ; rudi- 

 mentary limbs of, 67; nictitating 

 membrane of, 75 ; branchial 

 arches of, 150; embryology of, 

 152 ; palaeontology of, 163, 165, 

 178-180; brain of, 194-197; 

 distribution of, 224-240. 



Rhinoceros, foot of, 186. 



Robinson, Dr. L., on grasping 

 power of an infant'shands, 80-82. 



Rudimentary organs, 65-97- 



Ruminants, palaeontology of, 167, 

 168. 



Sacrum of man, compared with 



that of apes, 82-84. 

 Sagitta, 138. 

 Salamander, young of terrestrial, 



living in water, 102; embr)o 



logy of, 152. 



Sandwich Islands, 234-237. 

 Science, method of, 1-9. 

 Sclater, W. L., on a case of 



mimicry, 331, 332. 

 Scorpion in Silurian formation, 



163. 

 Sen, lamprey, 148; destructive 



agency of the, 423, 424. 

 Seal, 51, 52, 75. 

 Seasonal changes of colour, 317- 



3!9. 



Selection, value, 275 ; by physical 

 processes, 282, 283, 335. See 

 also Natural selection, Artificial 

 selection, Sexual selection, Phy- 

 siological selection. 



Sentiency, in relation to the 

 theory of evolution, 417. 



Sex, difference of, restricted to 

 Metazoa and Metaphyta, 105. 



Sexual reproduction, see Repro- 

 duction. 



Sexual selection, theory of, 277, 

 378410; statement and evi- 

 dences of, 379- '9 1 ; criticisms 

 of, 391-400; includes law of 

 battle with that of charming, 

 385. 386; in relation to religious 

 thought,4i 1-418 ; Tylor's theory 

 substituted for, by Wallace, 449, 



45- 

 Shark, eye of, 75 ; man-eating 



149 ; and pilot-fish, 289. 

 Sheep, limb-bones of, 176, 177; 



portraits of, 310. 

 Shells, of crabs, 62-64 ; palaeon- 



tology of mollusk's, 199-203 ; 



land on oceanic islands, 224- 



240. 

 Silliman's Journal, on fauna of the 



Mammoth Cave, 70. 

 Skate, electric organ of, 364-373- 

 Skull, palaeontology of, io.4-]<;9; 



of bull-dog compared with that 



of deer-hound, 307. 

 Slavonia, Tertiary deposits of, 



18, 19. 

 Species, not eternal, but either 



created or evolved, 13 ; named 



as such through absence of 



