COURTSHIP AND DISPLAY 201 



back door. He then becomes brilliant blood-red on 

 the belly (he was white before) and dark green on the 

 back, and swims about near the nest, and has an 

 occasional fight with a competitive neighbour, whilst 

 hustling and shepherding any female stickleback he may 

 meet so as to make her enter it. She enters it alone, and 

 lays an egg, or, perhaps, two or three, and then goes out 

 by the back-door ! The male, well pleased, at once goes 

 into the nest, fertilizes the eggs, and swims out again to 

 get another contribution to his future family. After 

 several females have thus deposited eggs in his nest, 

 and he has fertilized them, he keeps guard for many 

 days whilst the young are developing. Even when 

 they are hatched he is in constant attendance on them, 

 for there is danger of their being eaten — not by other 

 males, who are as busy as he is, but by the emancipated 

 females, who neither build the nest nor care for the 

 young, but just lay an egg here and an egg there when 

 invited, and pursue a selfish life of amusement and 

 voracious feeding. 



It is still doubtful how far male insects of the 

 true six-legged group appeal to the females by colour- 

 display, even when they are brightly coloured, or in 

 other ways than by perfumes (which they do very 

 generally), but among the spiders there are some kinds 

 (not common ones) in which the males have on the 

 front of the body one or two extraordinarily brilliant 

 spots of colour (red, apple-green, or yellow). The 

 male moves round the female in courtship, and poses 

 himself in most curious attitudes, so as to exhibit the 

 brilliant colour to her ; forcing it, as it were, on her 

 attention. In other species of spiders the male dances 

 and circles round the female, making curious and definite 

 antics. Some spiders also have rasp-like organs, with 



