This short paper, an abstract of the author's 'The Meaning of Animal Colour and Adornment' provides unwittingly some interesting fresh confirmation of the Freudian theory. For reasons the writer gives, Darwin's views about the meaning of animal coloration, i.e. that they were due mainly to sexual selection, have never gained wide acceptance. The writer now propounds the view that they are related rather to the intimidating aspects of pugnacity. By logical steps he reaches the generalization that the sexual instinct arouses intense hostility from aggressiveness against rivals, and that this can be allayed only by successful sexual union. He thus confirms, not only the Oedipus theory, but also the analytical view of the close fusion between sexuality and aggressiveness.