XVI. 
INDEX. 
Selaginella convoluta : migratory 
action of, 288. 
Selenio illunaria : protective col 
ouration of, 175. 
Semper, Karl : on protective col 
ouration amongst butterflies, 173 ; 
on colouration of white weasel, 
188; of arctic foxes, 191 ; on 
variation in artemia, 537 ; on 
sensitiveness of pond-snail, 538- 
40. 
Serpents : v. Snakes. 
Sexual Selection : its hostility to 
Natural Selection, 36-40 ; diffi 
culty in its acceptance, 37-41 ; 
illustrated by facts of domestica 
tion, 148-50. 
Carleton on, 36 ; 
Darwin on, 36, 37-8, 38-9, 39-40, 
68-9 ; Galton on, 36. 
Shakespeare, William : quota 
tion from As You Like It, 99 ; 
from Henry IV. (on instinct), 258 ; 
from Macbeth (on parental devo 
tion of wren), 81 ; from Merchant 
of Venice (on marriage), 40 ; (on 
chance), 65,66 ; from Midsummer 
Night's Dream (on love), 38 ; 
from Pericles (on appearances), 
208 ; from Richard II. (on physi 
cal heredity), 364 ; (on isolation), 
379 ; from Richard III. (on abor 
tion), 496 ; from Taming of the 
Shrew (on rudiments), 496 ; from 
A Winter's Tale (on chance), 60 ; 
(on nature and art), 131-2. 
Sheep : isolation in breeding, 380 ; 
influence of external conditions 
on, 397, 423- 
Ancon Ram : an illustration 
of Law of Correlated Variation, 
334, 357-60, 551 ; isolation in 
breeding, 381. 
Creolla : adaptation to en 
vironment of, 282-3. 
Sheep-breeding : Artificial Selec 
tion in, 139. 
Shrimps : protective habits 0^184-5. 
Sivatherium giganteum : an illus 
tration of Organic Evolution, 552. 
Skate : inutility of electric organ of, 
521-2. 
Skunk : warning colouration and 
effluvium of, 209-12. 
Slater, J. W. : his researches on 
tannin in animals, 404. 
Smell, Nauseous : protective cha 
racter of, 215-20. 
Snails ; co-operation amongst, 95 ; 
too low to possess instinct, 235 ; 
instinct in, 236. 
Pond- : sensitiveness of, 
538-40. 
Snakes : organic structure of, 509 ; 
influence of environment on 
birth-giving in, 542-3. 
Snow-bunting : colouration of, 
188. 
Sociability, Animal : 88 ; amongst 
birds, 88-9 ; ruminants, 89. 
Somerville, William : TheChase 
quoted, 183, 184, 239. 
Sousliks : sudden disappearance 
of, 53- 
Spalding, Douglas A. : on ani 
mal instinct, 230. 
Sparrows: imported into New Zea 
land, 51 ; intelligence in, 250. 
Special Creation : 470-4. 
Species : rarity of, 57 ; stability of, 
2 93-9 ! extinction of, 314-28 ; 
transmutation of—v. Transmu 
tation of Species. 
Spence, William : on instinct in 
insects, 234. 
Spencer, Herbert: his definition 
of evolution, i ; on meaning of 
evolution, 311 ; on Survival of 
Fittest, 14, 23, 565 ; amongst pro- 
tophytes, 569; amongst men, 582 ; 
on instinctive action in man, 243 ; 
on relation of Natural Selection 
to stability of species, 298 ; on 
results of cessation of Natural 
Selection, 301 ; on extinction of 
species, 316 ; on distinction be 
tween growth and development, 
447 ; on Special Creation, 461 ; 
on non-identity of Organic Evo 
lution and Natural Selection, 
452 ; on Natural Selection in re 
lation to Organic Evolution, 556- 
83 ; passim (thorns and hairs of 
plants, 559; nauseous taste in 
plants, 559 ; relations of tendons 
and bones, 560-2 ; use and dis 
use, 562-3 ; other factors, 563-4 ;