324 
Snail, experiments and investiga- 
tions on educability of, 55- 
61. 
Sooty terns, 
on, 1-6. 
Sounds, country, generally restful 
and subdued, 103, 105. 
Spencer, Herbert, runs away from 
home at thirteen, 192. 
his conviction that a night answer 
must be given to the question 
whether acquired characters are 
or are not inherited, 221. 
Spring, biology of, 151. 
its coming, on the moor of 
Dinnet, 150. 
homing experiments 
Squirrels, their storing instincts, 
188, 
Starfishes, shedding a limb, 166, 
167, 169. 
Stevenson, R. L., quoted, 113. 
Storing instinct, 183-190. 
among birds, 187. 
among insects, 184-187. 
among mammals, 188-189. 
in man, 189-190. 
Story as to “young seals” being 
“so like birds,” 9. 
Stout, Professor, quoted, on smell, 
or. 
Sweet Vernal grass, 95. 
Tadpoles, Gudernatsch’s experi- 
ments on, 147. 
their power of regrowing parts, 
168. 
See also Frog. 
Tapeworms, 198, 200. 
Technique of the experiments on 
homing of sea-swallows, 2. 
Technitella, 280, 282, 284, 286. 
Thompson, Miss Elizabeth Lock- 
wood, her experiments on 
snails, 56-61. 
Tower, Professor, his experiments 
on potato-beetles, 241. 
INDEX 
Tregarthen, J. C., his observations 
on the otter, 120-126, 
Troglodytes, 246-247. 
Trypanosomes, 198, 202. 
Tschermak, 232. 
Twins, biology of, 158-165. 
Galton’s investigations on, 
164. 
Siamese, 159. 
similarity between, 162-164. 
Van Hoff’s law of the effect of 
temperature on chemical re- 
actions, 129. 
Verhoeff, on wasp-community, 30. 
Vigor, acquired, does it count? 
263-269. 
Vigor and Heredity, Mr. J. Lewis 
Bonhote’s book, 264-265. 
Wasp, solitary, 
nest, 207-208. 
Wasps, African, 26, 28-31. 
social life of, 24-31. 
their family coherence, strength, 
and ingenuity, 25-26 
their instinctive behavior, 270, 
27%. 
their wonderful workmanship of 
their nest, 24-25, 115. 
Watson, Professor J. B., his experi- 
ments on homing of sea- 
swallows, 1-8. 
his observations on the duration 
of the nesting impulse, 7. 
Weismann, Professor, 155, 
229, 230, 255. 
Werber, his physiological theory, 161. 
Whales, Baleen, 72, 73. 
Black North Atlantic or Biscay, 
71, 75. 
Black Right, 78. 
Finback, 71. 
Greenland, or Bowhead, 78. 
Humpback, 71. 
Right, the fitness of, 71-79. 
Whales, Sperm, 71. 
162- 
its perfection of 
223, 
