FISH OF CEYLON. 



135 



The second set of experiments was tried in the presence of the 

 Kevd. G. Schrader, Revd. W. F. Kelly, and W. J, Sendall Esq., 

 Mr. Molesworth having suggested that the death of some of the 

 fish formerly experimented on, might have been accelerated by the 

 alarm experienced by them on finding themselves confined in so 

 small space as that of a glass receiver, it was determined to attempt 

 to keep the fish from access to the air, in this second set of experi- 

 ments, by means of diaphragms fastened a couple of inches beneath 

 the surface. 



Two vessels were employed. One was the bell glass of a hang- 

 ing lamp. In it were two Connias and two Loolas (both air breath- 

 ers,) and about fifteen or twenty Tittyas (water breathers). These 

 fish had been in the bell glass for some days; but were evidently 

 too much crowded, as the Tittyas, although the water was frequent- 

 ly changed, were constantly at the surface breathing air, as such 

 fish will do when the water becomes impure. The diaphragm in 

 this case was a circular piece of tin, perforated with small holes. 

 The other vessel was a tank or aquarium of the following dimen- 

 sions, viz. 36 x 16 x 12 inches. In it were a considerable number 

 of fish, both air-breathers and water-breathers. A diaphragm of 

 Mosquitos net was stretched across it, about two inches below the 

 surface, by means of pieces of rattan. These arrangements having 

 been made, the fish were left undisturbed for upwards of an hour. 

 On their being examined at the end of that time, all the air breath- 

 ers in the bell glass were found dead; but so also were about one 

 half of the water-breathers, whose death was probably attributable 

 to the fouling of the water, the volume of which was not sufficient 

 for the support of so many fish, especially when they were cut off 

 from all communication with the air. 



In the larger vessel, the diaphragm was found to be imperfect; 

 several of the fish, both air-breathers and water-breathers, had 

 made their way into the space above it, and it is probable that 

 some of those which were found below it, when the vessel was 

 examined, had, during the course of the experiment, passed repeat- 



