INDEX 



Accident, Darwin's use of the 

 word, 334-340 ; beauty due to, 

 408, 409. 



Achromatin, 126-134. 



Acquired characters, see Characters. 



Acrcea eurita, 328. 



Adaptation, facts of, in relation 

 to theory of natural selection, 

 401-403, 411. 



Adaptive characters, .^Characters. 



Esthetic sense in animals, 380- 

 385 ; see Beautiful. 



Agassiz, Prof. A., on fauna of the 

 Mammoth cave, 70. 



Alpine plants, 209, 210, 440- 

 442. t 



Amauns niavius, 328. 



Amblyornis inornata, 381-383. 



Amphioxus, 137, 138, 145, 146. 



Analogy, 38, 50-65, 176, 177, 

 347-350. 



Anthropoid, see Apes. 



Antlers, 98-100, 167-169. 



Ants, co-operative instincts of, 

 268 ; leaf-cutting, 332 ; keeping 

 aphides, 292. 



Ape, eye of, 75 ; appendix vermi- 

 formis of, 84-86. 



Apes, ears of, compared with those 

 of man, 88 ; muscles of, 77, 82, 

 83; feet of, 77, 78; tail of, 

 compared with that of man, 

 82-84 ; hair of, compared with 

 that of man, 89-91 ; teeth of, 

 compared with those of man, 

 92-94; flattening of tibiae of, 



95, 9 6 - 

 Aphides, 292. 



Appendix vermiformis of man 

 cumpared with that of orang, 

 84-86. 



Apteryx, 68, 69. 



Archtzopteryx, 171-173. 



Arctic plants, 209, 210, 440-442. 



Argyll, Duke of, on natural selec- 

 tion, 334-362. 



Aristotle, his idea of scientific 

 method, i ; on classification, 

 33, 24. 



Arm, distribution of hair on, in 

 man and apes, 89-92. 



Arthropoda, embryology of, 155. 



Artificial selection, analogy of, 

 to natural selection, 295-314: 

 pictorial representations of pro- 

 ducts of, 298-312. 



Artiodactyls, 182-191. 



Association, principle of, in 

 aesthetics, 404-407. 



Aster, 129-133. 



Attraction-spheres, 128, 132, 133. 



Australia, fauna of, 204, 205 ; 

 thriving of exotic species in, 

 286 ; portrait of wild dog of, 



34- 

 Azores, 224, 225. 



B. 



Bacon , Lord , on scientific method , 2 . 

 Balanoglossus, 147, 148. 

 BaptanoJon discus, posterior limb 



of, i"79-i8i. 

 Barriers, in relation to geographical 



distribution, 216-224. 

 Bats, 56, 224, 226, 240. 

 Battle, law of, 385, 386. 

 Bay a- bird, 381. 



Gg 2 



