Fishes. 44 1 3 



would then dive head foremost into the nest, and bring out a mouth- 

 ful of mud, which it would carry 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, the strongest being permitted to recreate themselves among 

 the Confervae that grew on a stone about 2 inches from the nest. On 

 the fourth day the fanning had ceased altogether, and the rambles of 

 the young were less restricted. They were not yet, however, permit- 

 ted 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 h e 

 fatal boundary was immediately devoured by the other fish, which 

 now seemed always on the watch, neglecting its own barren nest, 

 being intent only on appropriating to itself the nestlings of its fruitful 

 neighbour. In this act of cannabalism we see the reason for the pa- 

 rent'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, however, have other ene- 

 mies as well as their own species. One day a favourite Hydra, 

 H. fusca, was observed to be distended in a most extraordinary man- 

 ner; 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 pro- 

 jecting out of its mouth, had been seized upon by another Hydra. 

 Thus, it would appear that these low organized, but powerful and vo- 

 racious animals, occasionally regale themselves on the flesh of the 

 Vertebrata. 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 of their crystal abode. 

 Henceforth the parent's assiduity gradually relaxed, though for days 

 afterwards it was its custom to take the young occasionally into its 

 mouth, and after carrying them a little distance to let them drop out 

 again. I took one of the fry out one day for examination with the 

 microscope ; on returning it to the trough, it was in so sickly a state 

 XII. 2 31 



