386 THE DESCENT OF MAN. 



color at all other seasons of the year. The tench, roach 

 and perch may be given as instances. The male salmon 

 at this season is '" marked on the cheeks with orange- 

 colored stripes, which give it the appearance of a Labrus, 

 and the body partakes of a golden-orange tinge. The 

 females are dark in color, and are commonly called black- 

 fish."* An analogous and even greater change takes place 

 with the Salmo eriox or bull trout ; the males of the char 

 (S. umlla) are likewise at this season rather brighter in 

 color than the females. \ The colors of the pike (Esox 

 reticulatus) of the United States, especially of the male, 

 become, during the breeding-season, exceedingly intense, 

 brilliant, and iridescent. J Another striking instance out 

 of many is afforded by the male stickleback ( Gasterosteus 

 leiurus), which is described by Mr. Warington, as being 

 then " beautiful beyond description." The back and eyes 

 of the female are simply brown and the belly white. The 

 eyes of the male, on the other hand, are " of the most 

 splendid green, having a metallic luster like the green 

 feathers of some humming-birds. The throat and belly are 

 of a bright crimson, the back of an ashy-green, and the 

 whole fish appears as though it were somewhat translucent 

 and glowed with an internal incandescence." After the 

 breeding-season these colors all change, the throat and 

 belly become of a paler red, the back more green, and the 

 glowing tints subside. 



With respect to the courtship of fishes, other cases have 

 been observed since the first edition of this book appeared, 

 besides that already given of the stickleback. Mr. "W. S.' 

 Kent says that the male of the Lair us mixtus, which, as 

 we have seen, differs in color from the female, makes " a 

 deep hollow in the sand of the tank, and then endeavors in 

 the most persuasive manner to induce a female of the same 

 species to share it with him, swimming backward and for- 

 ward between her and the completed nest, and plainly 

 exhibiting the greatest anxiety for her to follow." The 

 males of Cantliarus lineatus become, during the breeding- 



* Yarrell, " British Fishes," vol. ii, 1836, pp. 10, 12, 35. 

 f W. Thompson, in "Annals and Mag. of Nat. History," vol. vi, 

 1841, p. 440. 



t" The American Agriculturist," 1868, p. 100. 

 " Annals and Mag. of Nat. Hist.," Oct., 1853. 



