316 MR. HANCOCK ON THE NIDIFICATION OF 



culate about the eggs. The parent would then dive, head fore- 

 most into the nest and bring out a mouthful of mud, which it 

 would cany to some little distance and discharge with a puff. 



The third day was passed much in the same manner, only as 

 the eggs were now all hatched, the nest was less frequently fanned 

 or ventilated ; and the fry, about forty in number, were allowed 

 greater liberty j the strongest being permitted to recreate them- 

 selves among the Confervse that grew on a stone about 2 inches 

 from the nest. On the fourth day the fanning had ceased alto- 

 gether, and the rambles of the young were less restricted. They 

 were not yet, however, permitted to pass beyond certain limits ; 

 when any transgressed these bounds they were immediately seized, 

 as heretofore, and carried back to the nest ; into which they were 

 always very glad to escape from the clutches of their ardent 

 parent. Notwithstanding all her vigilance, one contrived, on the 

 fifth day, to escape her eye, and passing the fatal boundary was 

 immediately devoured by the other fish, which now seemed 

 always on the watch, neglecting its own barren nest, being in- 

 tent only on appropriating to itself the nestlings of its fruitful 

 neighbour. In this act of cannibalism we see the reason for the 

 parent's anxious care and its jealousness of its kind ; and it is 

 evident from Mr. Crookenden's account, previously quoted, that 

 they greedily devour each other's spawn. The young fry, how- 

 ever, have other enemies as well as their own species. One day 

 a favourite Hydra (H. fusca) was observed to be distended in a 

 most extraordinary manner ; on examination, it was found to 

 have swallowed the head and shoulders of one of the young fish 

 many times larger than itself ; and the caudal extremity, which 

 was too much for it, and which was projecting out of its mouth, 

 had been seized upon by another Hydra. Thus, it would appear 

 that these low organized, but powerful and voracious animals 

 occasionally regale themselves on the flesh of the Vertehrata. 

 This happened when the fry were three or four weeks old. 



All the old fish, with the exception of that with the young, 

 were, in consequence of their cannibal propensities, turned out 

 of the trough ; and danger being thus removed, the fry were no 

 longer restricted in their rambles, but enjoyed the whole range 



