80 Gen . Sub . 
I. GENERAL SUBJECTS. 
females ; ( e ) the evidence for artistic discrimination even in higher 
animals, such as the Argus pheasant, is very weak; (/) even in man 
deliberate artistic selection seems much rarer than is usually supposed. 
II. Special criticism from the case of the wall-lizard : — The variability 
of ornamental design is not adaptive to environment, nor is preferential 
mating (on an aesthetic basis) known to occur. “ The severe struggle for 
existence, and the predominance which forms like nigriventris have been 
able to assert over less pigmented forms, afford demonstrative evidence 
that abundant pigmentation, the expression of intense metabolism, 
must be associated with superior physical vigour”; Douglass (156). 
— Extinction of species, factors in ; not hostile aggression, not lack of 
food, probably adverse natural changes and competition. Perhaps giant 
reptiles yielded to egg-destroying mammals ; Morris (480). — Struggle 
for existence in the Alps ; Galli-Valerio (225). — Casual variations in 
abyssalEchinoderms, conserved by isolation and in some cases by natural 
selection, but many non-utilitarian ; Yerrill (710). 
Studies of nature iu relation to the struggle for life ; Rodway (581). 
— An attempt to measure the death-rate due to the selective destruction 
of Carcinm mamas with respect to two particular dimensions ; Weldon 
(741). 
Altruistic impulse in man and animals ; Gavanescul (289). 
Isolation ; Thomson (689). — Differentiation of species on the Galapagos 
Is. ; Baur (25). 
e. Particular Problems. 
Structure of man : an index to his past history; Wiedersheim (756). 
— The origin of man ; Haacice (268). 
Phylogeny of Vertebrata ; Haeckel (274), Gaskell (236), Goette (249). 
Rudimentary eyes of Vertebrates illustrate an inhibited develop- 
ment where function is in part retained, or degeneration where the func- 
tion of the whole or part is lost. But degeneration is preceded by 
inhibition. The direct or indirect condition is the absence or lack of 
light; Kohl (351). 
Polydactylism, with special reference to its aetiology; Harms (and 
others not recorded) (286). 
Joints, origin of; Hammab (281). 
Arclieuteron, &c., origin of; MacBride (416). 
^Etiological problems illustrated in relation to Lepidoptera ; Garbowski 
(231). —Evolution of species in Lepidoptera ; Eimer (174). — The uses of 
colour to insects in the struggle for existence ; Poulton (533). — Colour- 
marking of Hiruditiea not hereditarily fixed, but individually acquired in 
the course of metabolism ; Graf (255). — Pigmentation of wall-lizard ; the 
variability of ornamental design, even from one locality, shows that the 
designs are not adaptive ; nor is their explanation to be found in sexual 
selection, for no aesthetic choice of males occurs ; abundant pigmentation 
seems correlated with superior physical vigour ; Douglass (156). — 
