136 CHILDHOOD OF ANIMALS 



larvae grew suckers on their heads Hke those of tadpoles, with 

 which they fastened themselves to the sides of the nest. In the 

 same locality Budgett found the floating nests of Gymnarchus 

 niloticus, which were a foot and a half across and surrounded on 

 three sides with a rim of twisted weeds, the fourth side being 

 under the level of the water. The male kept a fierce watch over 

 the larvae in the nest, snapping viciously at intruders. The 

 fantang {Heterotis niloticus) makes a nest four feet across with a 

 rim eight inches high, composed of the stems of grasses. In 

 making its nest the fish swims round and round, throwing its tail 

 upwards and outwards, and so tossing on the growing wall the 

 debris it removes from the central area. Soon after the larvae 

 hatch they are taken out on trial swimming trips by the parent, 

 but return to their home. When they leave it finally, the parent 

 still keeps with them for a time. The bow-fin of the great lakes of 

 America leaves deep water in spring and moves to swampy shallows. 

 There they break up into little parties, each consisting of a female 

 and several males. The fish of one party construct a rude nest 

 by wriggling round and round in the mud until they clear a circular 

 area. In these the eggs are laid, and one of the males mounts 

 guard, the rest of the party dispersing. When the young finally 

 leave the nest, they are accompanied and^protected by the guardian 

 parent for a time. 



The American buUheads or horned pouts resort in pairs to the 

 muddy shallows at the edges of the fresh- water lakes they inhabit. 

 In water a few inches deep they gradually make a hollow in the 

 side of the bank, throwing out the mud and sand until a mound is 

 formed on the bottom with a shallow groove leading to the opening 

 into the nest. The excavation is done with the head, and although 

 both male and female share in the work, the latter is more zealous. 

 Sometimes the nests are made in the hollow, submerged stumps of 

 trees, sometimes scooped out amongst reeds and bulrushes. After 

 the eggs are laid, one or both parents remain to guard the young 

 larvae, and then swim out with the shoals of little fish. Shoals 

 from different nests have been observed to join temporarily, but 

 afterwards to separate, so that it seems as if the corporate life had 

 led to a definite sense of recognition amongst the members of each 

 brood. 



The nesting habits of the little sticklebacks which live in fresh, 

 brackish or salt water are well known. The male is the house- 

 builder, and uses weeds and twigs as his material, fastening them 



