loo The Study of Animal Life part i 



male salmon, with their hooked lower jaws, fight with their 

 rivals, sometimes to the death. 



Among insects the love-play is again very lively. Like 

 birds, many of these active animals are very beautiful in 

 colour and form, especially in the male sex, and a display of 

 charms has often been noticed. Like birds, though in a 

 different fashion, some of them are musical, using their 

 hard legs and wing-edges as instruments. The crickets 

 chirp merrily, the cicadas " sing," and the death-watch taps 

 at the door of his mate. 



In the summer night, when colours are put out by the 

 darkness, the glow-worm shines brightly on the mossy bank. 

 In the British species (Lampyris nocHluca) the winged 

 male and the wingless female are both luminous ; the latter 

 indeed excels in brightness, while her mate has larger eyes. 

 Whatever the phosphorescence may mean to the constitution 

 of the insect, it is certainly a love-signal between the sexes. 

 But we know most about the Italian glow-worm {Luciola 

 italica), of whose behaviour we have a lively picture — thanks 

 to Professor Emery's nocturnal observations in the meadows 

 around Bologna. The females sit among the grass ; the 

 males fly about in search of them. When a female catches 

 sight of the flashes of an approaching male, she allows her 

 splendour to shine. He sees the female's signal, and is 

 swiftly beside her, circling round like a dancing elf. But 

 one suitor is not enough. The female attracts a lev^e. 

 In polite rivalry her devotees form a circle and await the 

 coquette's choice. In the two sexes, Emery says, the 

 colour of the light is identical, and the intensity seems 

 much the same, though the love-light of the female is more 

 restricted. The most noteworthy difference is that the 

 luminous rhythm of the male is more rapid, with briefer 

 flashes ; while that of the female is more prolonged, with 

 longer intervals, and more tremulous — illumined symbols of 

 the contrast between the sexes. 



While recognising the genuinely beautiful love-making of 

 most birds, we did not ignore that the courtship of most 

 mammals is somewhat rough. So, after admiring the love 

 dances of many butterflies, the merry songs of the grass- 



