INDEX 
A. 
Accident, Darwin's use of the 
word, 334-340; beauty due to, 
408, 409. 
Achromatin, 126-134. 
Acquired characters, see Characters. 
Acrea eurita, 328. 
Adaptation, facts of, in relation 
to theory of natural selection, 
401-403. 411. 
Adaptive characters, see Characters. 
Esthetic sense in animals, 380- 
385; see Beautiful. 
Agassiz, Prof. A., on fauna of the 
Mammoth cave, 70. 
Alpine plants, 209, 
442.0 
Amauris niavius, 328. 
Amblyornts tnornata, 381-383. 
Amphioxus, 137, 138, 145, 140. 
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; laa vermt- 
Jormis of, 84-S6. 
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 tibiz of, 
95» 90. 
Aphides, 292. 
210, 
440- 
Appendix vermiformis of man 
compared with that of orang, 
84-86. 
Apleryx, 68, 69. 
Archaeopteryx, 171-173. 
Arctic plants, 29, 210, 440-442. 
Argyll, Duke of, on natural selec- 
tion, 334-362. 
Aristotle, his idea of scientific 
method, 1; on classification, 
23, 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, 203; 
thriving of exotic species in, 
286; poitrait of wild dog of, 
304. 
Azores, 224, 225. 
B. 
Bacon, Lord, onscientific method,2. 
Balanoglossus, 147, 148. 
Baptanodon discus, posterior limb. 
of, 179-181. 
Barriers, inrelation to geographical 
distribution, 216-224. 
Bats, 56, 224, 226, 240. 
Battle, law of, 385, 386. 
Baya- bird, 381. 
Gg2 
