Page:Natural History, Fishes.djvu/18

4 preponderates, while in those of fresh-water, it is largely, or wholly composed of nitrogen.

The following fact recorded by Mr. Jesse shows that the possession of an air-bladder may, under some circumstances, expose fishes to danger.

“On the 9th, 10th, and 11th days of April, 1837, a friend of mine, then residing at Hastings, observed several fish ﬂoating on the surface of the water, and men and boys wading in, and pulling them out, the fish apparently making no effort to escape. On inquiry, he found that they were all Gurnards, no other fish exhibiting this phenomenon at that time, although he was informed that, a few years before, some Conger Eels were, during severe weather, in the same predicament.

“Some of the fishermen attributed the helplessness of the Gurnards to the circumstance of their having been blinded by the cold. Others said, the fish mistook the flakes of snow, which fell on the surface of the sea, for insects; and that, by leaping up so constantly and eagerly, for the purpose of catching them, they at last ‘blew themselves;’ meaning, that they so distended the air-bladder, that it lost its elasticity, or power of contraction, and thus they became helpless. On inspecting a ﬁsh just caught, the eyes were perfect; but upon opening the abdomen, and removing the air-bladder, the latter was found extremely distended. It is probable that the Gurnards came into shallow water in search of food, and the shallow water being much colder than the deep water, the fish became so benumbed, that when they had once distended the air-bladder to mount to the surface, the muscles had not power to compress it, and hence