82 THE ANGLER-tfATURALIST. 



whilst the Ten-spined species, on the contrary, select for 

 a building-site the broad leaves or fibrous roots of aquatic 

 plants. The two former build nests in shape somewhat 

 like mole-hills, while the nest of the latter rather resem- 

 bles a muff, or the nest of the Wren, or Long-tailed Tit. 

 On the approach of the spawning-time, which is about 

 May, or a little later in the summer, the male commences 

 operations by collecting in a convenient locality a quantity 

 of grass-stalks, wiry water-mosses, and other fibrous mat- 

 ters, which he cements with the mucus that exudes from 

 his skin, creeping for this purpose backwards and forwards 

 over the materials. In the Smooth-tailed species, the foun- 

 dation is usually laid of straws, having their ends carefully 

 tucked into the gravel ; other straws are laid across, and 

 similarly secured by the fish placing his snout on the end 

 of each straw, and then raising his body vertically so as to 

 press it down. Confervas and such like are then woven 

 into a mass above, through which the water can have free 

 passage. In the centre of this a dome-like hollow is pre- 

 served, and on the top a small round hole, the edges of 

 which are strengthened with particular care, and rounded off 

 by tucking in the loose fibres ; whilst every now and then 

 the architect pauses in his task and hovers over the nest, 

 agitating the water with his fins as if to try the stability of 

 the structure. In the Rough-tailed species the bottom of 

 the nest is first finished, then the sides, and lastly the top, 

 which is covered carefully over, a small hole being left on 

 one side for an entrance. This labour completed, the 



