Natural Selection and Tropical Nature; Essays on Descriptive and Theoretical Biology (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1891 edition. Excerpt: ... THE COLOURS OF ANIMALS AND SEXUAL SELECTION1 General Phenomena of Colour in the Organic World--Theory of Heat and Light as producing Colour--Changes of Colour in Animals produced by Coloured Light--Classification of Organic Colours--Protective Colours--Warning Colours--Sexual Colours--Normal Colours--The Nature of Colour--How Animal Colours are produced--Colour a normal product of Organisation--Theory of Protective Colours-- Theory of Warning Colours--Imitative Warning Colours--The Theory of Mimicry--Theory of Sexual Colours--Colour as a means of Recognition--Colour proportionate to Integumentary Development--Selection by Females not a cause of Colour--Probable use of the Horns of Beetles--Cause of the greater Brilliancy of some Female Insects-- Origin of the Ornamental Plumage of Male Birds--Theory of Display of Ornaments by Males--Natural Selection as neutralising Sexual Selection--Greater Brilliancy of some Female Birds--Colour-development as illustrated by Humming-Birds--Theory of Normal Colours-- Local causes of Colour-development--The influence of Locality on Colour in Butterflies and Birds--Sense-perception influenced by Colour 'of the Integuments--Summary on Colour-development in Animals. General Phenomena of Colowr in the Organic World There is probably no one quality of natural objects from which we derive so much pure and intellectual enjoyment as from their colours. The heavenly blue of the firmament, the glowing tints of sunset, the exquisite purity of the snowy mountains, and the endless shades of green presented by the verdure-clad surface of the earth, are a never-failing source of pleasure to all who enjoy the inestimable gift of sight. Yet these constitute, as it were, but the frame and background of 1 A first sketch of...