56 Gen. &ub. 
i. general subjects. 
account for patterns, &c. The importance of the blood in bringing all 
parts of the body into connection. Secondary sexual characters believed 
to be cjue to the varying reactions of the organs of the body to the 
chemical stimuli -which pass out from tho sexual organs by tho blood ; 
Emery (147). 
Sexual selection ; Keeler (277). 
Natural selection among men ; Ammon (6), Munro (366). 
Skin-parasites as factors in natural selection ; Sciiewyriew (457). 
Isolation : the Lizard genu 3 Tropidurus in Galapagos Islands ; Baur 
(31). 
e. Particular Problems. 
Kinetogenesis of the limbs of Vertebrates ; Cope (108). 
Physical explanation of organic skeletal structures ; Dreyeii (134). 
Mechanical genesis of form of fowl's egg. Inquiry into the immediate 
conditions influencing shape of egg .... or even type of placenta. 
In case of egg-shell, the author distinguishes (a) the development of a 
statical equilibrium (statogenetic), and (6) the kinetic results of move- 
ment in oviduct (kinetogenetic) ; Ryder (442). 
“ Mechanical" genesis of joints in Crustaceans, &c . ; Sharp (473). 
“Mechanical" evolution of metapodial keels of Diplarthra] Wort- 
man (556). 
Coloration : Albinism and melanism in Reptiles and Amphibians ; 
Werner (542). — Markings of fish ; Saville-Kent (454). — Coloration 
of flat-fishes : “ These investigations afford support to the view that the 
incidence of light is the reason why the upper aud dorsal surface of animals 
is more strongly pigmented than the lower or ventral throughout the 
animal kingdom, and that the absence of light is the cause of the disap- 
pearance of pigment in many cave-inhabiting and subterranean animals 
Cunningham & MacMunn (118). — Colours of birds: Pigments, probably 
waste-products, vary in different groups ; natural and sexual selection com- 
bine and re-arrange the limited assortment. Law of assortment of pig- 
ments : the primitive colour is a composite, which, when more or less 
completely resolved into its component elements, gives the specialized 
tints of the species or genus ; Keeler (277). 
Evolution of pigments in Lephloptera, &c. : The simplest pigments are 
greenish-yellow to yellow ; with increasing molecular weight in the pig- 
ments, orange, red, violet, blue, and green may successively arise. Some- 
times in the ontogenetic succession of colour there is a recapitulation of 
the phylogenetic process [Cf. p. 40, Physiological] ; Urech (508). 
Luring colours in animals ; Strubell (496). 
Protective adaptations ; Hornell (253). — Protective colouring in 
birds; Fabani (155). — Protective colour in Lepidopterous larvas; Gould 
(197). — Colour-change in animals which turn white in winter ; Schwalbe 
(466).— Variations in colours of cocoons in reference to theories of prg^ 
tective colouration ; Bateson (29). 
