382 
twigs, 64; females resembling 
leaves, 112. 
Puyiuium, wonderful protective 
colour and form of, 64. 
Paysatta, 258. 
Pierrpz, local modification of 
form in, 172. 
Pizris, females only imitating 
Heliconide, 112. 
Pieris coronis, 172; eperia, 172. 
Pieris pyrrha, 118, 
Pci, sexual colouring and nidi- 
fication of, 242. 
Preripa, sexual colouring and 
nidification of, 245. 
Pirripa, 253. 
Pliocerus equalis, 101; P. elapoides, 
P. euryzonus, 102, 
Peciloderma terminale, 93. 
Potarity, Forbes’ theory of, 17, 
45, 
Potymorpuism, 145; illustration 
of, 157. 
Porutation of species, law of, 28; 
does not permanently increase, 
29; not determined by abun- 
dance of offspring, 29; checks 
to, 30; difference in the case of 
cats and rabbits explained, 32, 
Previston, a case of, 122. 
Prioniturvs, 196. 
Provrction, various modes in 
which animals obtain it, 69-71, 
258 ; greater need of, in female 
insects and birds, 113. 
Protective colouring, theory of, 
65. 
Psirtact (Parrots), sexual colour- 
ing and nidification of, 242, 
Prerosauria, 298, 
Prycuoperss, 94. 
INDEX, 
RACES, or subspecies, 160; of 
man, origin of, 319. 
Repsreast and woodpigeon, pro- 
tective colouring of, 53, 54. 
REPRESENTATIVE groups, 9; of Tro- 
gons, butterflies, &c., 12. ° 
Rerties, protective colouring of, 
54, 
RaamPuastip#, sexual colouring 
and nidification of, 242. 
Rarnoceros, 299. 
River system, as illustrating self- 
adaptation, 276. 
Roszs, Mr. Baker on varieties of, 
165. 
Rupmenrary organs, 23, 
SALVIN, Mr. Osbert, on a case of 
bird mimicry, 107. 
Saturnia pavonia-minor, protective 
colouring of larva of, 63. 
Saryrip2, probable means of pro- 
tection of, 176. 
Savrorrsryera, 299, 
Savaags, why they become extinct, 
319; undeveloped intellect of, 
339, 341; intollect of, compared 
with that of animals, 341, 343; 
protect their backs from rain, 
346. ; 
ScansoriA birds, nests of, 238. 
Scaruura, 98. 
Scissirostrum, 165, 
Scorunipepes, brush-legged bees, 
91. 
Scupper, Mr.,on fossil insects, 301. 
ScuTELLERID#, mimicked by Long- 
icorns, 96. 
Sesia bombiliformis, 90. 
Szs11p2, mimic Hymenoptera, 90. 
Sexes, comparative importance of, 
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