3674 The Zoologist — September, 1873. 



fish no other will use it ; they take hold of it, examine its capa- 

 bilities, and invariably reject it; thus proving that these little 

 creatures have some instinctive knowledge of its adaptability or 

 otherwise to the purpose required ; the occupations of searching, 

 finding, testing, examining, selecting and rejecting materials seems 

 incessant; sometimes, however, it will be interrupted by the ap- 

 pearance of an intruder, who is immediately made an object of 

 attack, seized, bitten, and compelled to retreat: the victor will chase 

 him round the glass for a few seconds, and then return and survey 

 his building; he is ever suspicious that it may have suffered 

 injury during ever so short an absence, and will hang in water, 

 like a Syrphus in air, with his head pointed towards his nest, until 

 he is assured that his nursery is intact : this Syrphus-like suspen- 

 sion is well worth studying; the little fellow, although perfectly 

 still at intervals, will often, with a kind of start, change his position, 

 and take up a new one on the other side of the glass, but still with 

 his nose pointing towards the object of attraction, " true as the 

 needle to the pole," and there he will hang hovering, and winnowing 

 the water with his fins, just as he had hung hovering before. After 

 awhile, assured that his building is intact, he will resume his 

 architectural labours. How often have I seen him, like a tailor- 

 bird, carry some little plant-fibre, or perhaps a fragment of thread 

 which I had dropped into the water for his especial use and benefit, 

 and watched him pass the end through and through the walls of 

 the nest, until it was adjusted to his mind ; how often have I seen 

 him stop when his body was half-way through the nest, his head 

 projecting on one side, and his tail on the other; how often have 

 I wondered by what seemingly miraculous power he passed through 

 the nest he had taken so much pains to construct — yes! pass 

 through it in any direction, as though, like Pepper's ghost, the nest 

 itself were an "airy nothing" which offered no resistance to his 

 compact body, thews and sinews, muscles and spines. From time 

 to time would he come forth, his eyes flashing fire, his breast 

 glowing with rosy red, and if no disturbing element was near would 

 contemplate his work with unmixed satisfaction ; then he would 

 go to work again. 



The question when or how the eggs are deposited, whether before 

 or after the building of the nest, is by no means finally ascertained. 

 Something like a love chase occasionally takes place, proving that 

 fishes are not altogether insensible to the tender passion, but such 



