154 The Ottawa Naturalist. [November 



mother-of-pearl, feathers of tropical birds, insects and shells. Sir 

 David Brewster found that the wax impression ot a pearl showed 

 rainbow colors like the original pearl. These "interference' 

 colors, due to striations on the surface, or to prism-like transparent 

 parts of animals, illustrate some of the most gorgeous effects 

 observable in living things. The silvery color of many animals is 

 not due to pigment or color, but to glistening smooth surfaces, 

 and thus must be classed merely as " specular reflection." 



Ancestral Coloration. The ocean is, as August Weissmann 

 declared, the original birthplace of all animal life. The simple 

 protozoan animals, and larval stages of higher forms, abounding 

 in the sea, are in most instances, of a colorless transparency, at 

 any rate in the earliest period of their lives. Even in such highly 

 organised creatures as the fishes, the minute embryos, at a very 

 early stage of development, are colorless and translucent. Further, 

 the body is not only colorless, but it is wormlike, segmented, or 

 metameric. Annelids, insects, crustaceans, mollusks, ascidians, 

 fishes, reptiles, nay even birds and the highest animals, may exhibit 

 a colorless metameric body. 



When color spots first appear in these, they are grouped 

 serially, thus forming transverse patches or stripes from the head 

 to the tail. This metameric coloring is very prevalent in the 

 young of all classes of animals. 



If the segmented body be ancestral, then there is strong pre- 

 sumption that repeated stripes and spots are ancestral also. They 

 persist even though their use and meaning may have gone. Like 

 the two buttons on a dress coat which served to hold up the sword- 

 belt when our forefathers were accustomed to carry swords ; but 

 are now of no use, though, thanks to the tailor, they still persist, 

 so we find transverse stripes, still appear as the first coloration in 

 a vast number of animals. 



A larval cod, a week or ten days after hatching out from 

 the egg, exhibits a series of black stripes, and the young salmon 

 and trout shew cross bars, or "parr marks," which may be readily 

 derived from the striped condition just referred to. Now, in some 

 young flat-fishes the bars along the sides of the body divide into 

 spots or large patches, four rows of them, and still preserving the 

 metameric or serial succession from the head to the tail. Thus 



