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Sexual Selection

Take Peacock-feather give woodcut — give gradations — Here only select general beauty. Laws of change — infinite difficulty — Though an action must be assumed from beauty — my greatest difficulty — Consider some few laws — Characters appear from descent from allied form — spangling & [illeg] in Hens. When a character appears in one part — by connection spreads — Hackles on crest of Poland— saddle hackles on G. bankiva black shaft— spreads. Where any bar or mark appears colours may be replaced — wings of pigeons— (Colour may spread symmetrically up shaft — In some cases the colour spreads symmetrically up the shaft as in cross from silver — Poland & Spanish cock. But what is more important when colour changes from one part of feather to other, a symmetrical border marks passage. (this chief wonder in Peacocks eye) Thus in cross Poland & Spanish — shaft greenish black — edge broadly brown white — intermediate dark brown) Mongrel from Spanish & white game whole feather black glossed with green, tipped with yellowish white — always symmetrical zone between of dark-brown. Again take case of bars of pigeon wings — New white zones of colour.

Spots of Butterflies