560 THE CLIMBING PERCH. 



forty yards from the tank. They were forcing their way up the knoll ; 

 and had they not been interrupted, first by the pelican and afterward 

 bv ourselves, they would in a few minutes have gained the highest 

 point, and descended on the other side into a pool which formed an- 

 other portion of the tank. 



"... As the tanks dry up the fish congregate in the little pools, till 

 at last you find them in thousands in the moistest parts of the beds, 

 rolling in the blue mud, which is at that time about the consistence of 

 thick gruel. 



"As the moisture further evaporates the surface fish are left uncov- 

 ered, and they crawl away in search of fresh pools. In one place I 

 saw hundreds diverging in every direction from the tank they had just 

 abandoned to a distance of fifty or sixty yards, and still travelling on- 

 ward. In going this distance, however, they must have used muscular 

 exertion enough to have taken them half a mile on level ground, for 

 at these places all the cattle and wild animals of the neighborhood had 

 latterly come to drink, so that the surface was everywhere indented 

 with footmarks in addition to the cracks in the surrounding baked 

 mud, into which the fish tumbled in their progress. In those holes 

 which were deep, and the sides perpendicular, they remained to die, 

 and were carried off by kites and crows. 



" My impression is that this migration must take place at night or 

 before sunrise, for it was only early in the morning that I have seen 

 them progressing, and I found that those I brought away with me in 

 the chatties appeared quiet by day, but a large proportion managed to 

 get out of the chatties by night. Some escaped altogether; others were 

 trodden on and killed. 



"One peculiarity is the large size of the vertebral column, quite dis- 

 proportioned to the bulk of the fish. I particularly noticed that all in 

 the act of migrating had their gills expanded." 



It is known of the Climbing Perch that the fishermen of the Ganges, 

 who subsist largely on these fishes, are accustomed to put them into an 

 earthen pan or chatty as soon as caught; and, although no water is 

 supplied to them, they exist very well without it, and live this strange 

 life for five or six days. 



On opening the head of this fish the curious structure which enables 

 it to perform such marvellous feats is clearly seen. Just within the 

 sides of the head the pharyngeal bones — i. e., the bones that support 

 the orifice between the mouth and gullet — are much enlarged, and mod- 

 ified into a series of labyrinthine cells and duplications, so that they 

 retain a large amount of water in the interstices and prevent the gill- 

 membranes from becoming dry. Some writers say that this fish is ca- 

 pable of climbing up the rough stems of palm trees in search of the 

 water that lodges between the bases of the dead leaves and the stem, 



