



THE OTTAWA f(ATURALISlSJL> 



Vol. XX. OTTAWA, NONEMBER, 1906. No. 8 



ANIMAL COLORATION. 



By Professor Edward E. Prixce, Dominion Commissioner of Fisheries, 



Ottawa. 



Many years ago I delivered the opening lecture in a course of 

 scientific addresses in the University of Toronto. I chose as my 

 subject the colors of animals, and the same theme has been dealt 

 with by me on several subsequent occasions. Apart, however, 

 from a short article, entitled " Spots and Stripes," in the London 

 " National Observer" and a brief notice in The Ottawa Natural- 

 ist in 1893, I have not published my views on this subject. 



It is a subject of general interest ; and many authorities, 

 Poulton, Beddard, Eimer, Garstang, and others, have treated it 

 more or less fully ; but as Professor Mcintosh, in the "Annals of 

 Natural History " last year, pointed out, very many of the theories 

 offered are wholly inapplicable to some of the most familiar and 

 striking iases of animal coloration 



My own conclusion is that pelagic animals, the small colorless 

 creatures abounding at the sea's surface, are primitive. All 

 animal life was originally colorless and possibly transparent, like 

 glass. The first colors appearing in animals were due to vegetable 

 food, or to parasites, especially " plant commensals " ; but by- 

 products, resulting from digestive and other processes, also pro- 

 duced animal colors. Colors of a brilliant prismatic character 

 appeared, no doubt, in jelly-fishes and other transparent animals 

 in the seas of the early world. These rainbow tints may be due 

 to " thin plates" as discovered by Sir Isaac Newton in the soap- 

 bubble, and seen also in the wings of the house-fly, elytra of 

 beetles, scales on butterflies' wings, &c, or may be produced by 

 minutely grooved or striated surfaces, producing lustrous tints as in 



