376 THE DESCENT OF MAN. 



Salmonidae) are provided with a ridge of closely-set, brush- 

 like scales, by the aid of which two males, one on each side, 

 hold the female, while she runs with great swiftness on 

 the sandy beach and there deposits her spawn.* The 

 widely distinct Monacanthus scopas presents a somewhat 

 analogous structure. The male, as Dr. Giinther informs 

 me, has a cluster of stiff, straight spines, like those of a 

 comb, on the sides of the tail ; and these in a specimen 

 six inches long were nearly one and a half inches in 

 length; the female has in the same place a cluster of bristles, 

 which may be compared with those of a toothbrush. In 

 another species, M. peronii, the male has a brush like that 

 possessed by the female of the last species, while the sides 

 of the tail in the female are smooth. In some other 

 species of the same genus the tail can be perceived to 

 be a little roughened in the male and perfectly smooth in 

 the female; and lastly in others, both sexes have smooth 

 sides. 



The males of many fish fight for the possession of the 

 females. Thus the male stickleback ( Gasterosteus leiurus) 

 has been described as " mad with delight " when the female 

 comes out of her hiding-place and surveys the nest which 

 he has made for her. ' ' He darts round her" in every direc- 

 tion, then to his accumulated materials for the nest, then 

 back again in an instant; and as she does not advance he 

 endeavors to push her with his snout, and then tries to pull 

 her by the tail and side-spine to the nest."f The males are 

 said to be polygamists; J they are extraordinarily bold and 

 pugnacious, while "the females are quite pacific." Their 

 battles are at times desperate; " for these puny combatants 

 fasten tight on each other for several seconds, tumbling 

 over and over again, until their strength appears completely 

 exhausted." With the rough-tailed stickleback (G. tracliu- 

 rus) the males while fighting swim round and round each 

 other, biting and endeavoring to pierce each other with 

 their raised lateral spines. The same writer adds, "the 

 bite of these little furies is very severe. They also use their 



*" The American Naturalist," April, 1871, p. 119. 

 f See Mr. R. Warington's interesting articles in "Annals and Mag 

 of Nat. Hist.," Oct., 1852, and Nov., 1855. 

 \ Noel Humphreys, " River Gardens," 1857. 

 London's " Mag. of Nat. History," vol. iii, 1830, p. 331. 



