COURTSHIP AND NURSERY DUTIES. 107 



for a nest. The shell is placed with its con- 

 cavity downwards, beneath which the soil is 

 removed, and cemented together by, it is said, 

 a special secretion of the skin. In the stickle- 

 back, it will be remembered, the kidneys fur- 

 nished the necessary cement. Access to this 

 nest is gained by a cylindrical tunnel, and the 

 whole structure covered by loose sand. The 

 eggs are fixed to the shell by the female, and 

 left to the care of the male, who mounts guard 

 over them and remains on duty till hatching, 

 which takes place from six to nine days. 



CrenilabruSj one of the wrasses or lip-fishes, 

 builds a nest of sea-weed and shells, etc., in 

 which the eggs are deposited. But it is inter- 

 esting to note that in this instance at least both 

 male and female are engaged in its construction. 



One of the angler-fishes (Antennarius) builds 

 in the floating " gulf-weed " off the Bermudas, a 

 very beautiful nest. This is suspended by deli- 

 cate silken fibres, quite strong enough to sup- 

 port the large grape-like clusters of eggs within. 

 "Each nest is made of one seaweed, the different 

 twigs being brought together and made fast to 

 each other by the fish by means of a pasty sort 

 of substance provided by the animal itself." 



Perhaps one of the most remarkable of fish- 

 nests is that of one of the Chinese paradise fish 

 (Macropus). This is fashioned by the male, and 

 takes the form of a little disc of froth formed by 

 blowing air and mucus out of his mouth. The 

 nest made, he proceeds to collect the now fertil- 

 ised ova, dropped by the female, into his mouth, 

 and deposits them in his froth-like nest. This 



