LOVE-MAKING AMONG FISHES 183 



case of a closely-related species, less pugnacious in dis- 

 position, but almost as vividly coloured, in so far as the 

 male is concerned. Now in this species a nest of froth 

 is made and the eggs, after deposition therein, are 

 jealously guarded by the male. Hence, on these facts, 

 we may assume with a fair amount of certainty that the 

 closely-related " Fighting Fish " displays like habits. 



That the Reptiles, Amphibia and Fishes have much in 

 common with one another, and with the higher vertebrates, 

 in the manner of their love-making is indisputable. We 

 find no evidence anywhere that the first faint throbbings 

 of the sexual pulse in the female are quickened to fever 

 beats after the efforts of several successive wooers, each 

 more demonstrative than the last, to arouse this state 

 — the conditions required by the Sexual Selection theory. 

 But successful mating depends, in each year, on the 

 sexual fitness of the male himself, and the mate, or mates, 

 which for that year he has taken " for better or worse." 

 It is possible, of course, that a male, ambitious but im- 

 potent, will be forsaken by his mate ; it is possible that a 

 female of low sexual vitality may fail to respond to the 

 most impassioned displays; in either case no offspring 

 result, and thus the failures are eliminated. It is possible 

 that here, as with the higher vertebrates, coition may by 

 no means always be immediately preceded by display. 

 But the " display " has done its work. It has stimulated 

 the sexual appetite, as the sight of tempting food 

 stimulated the bodily appetite. 



But both the Amphibia and the Fishes reveal a lower 

 plane of the sexual instincts, when the sexes, dominated 

 by some imperious instinct, gather in hordes, commingling 

 to shed their precious germs into the surrounding water, 

 there to effect the work of fertilization and the achieve- 



