THE LAND OF A SINGLE TREE. 19 



merely by taking the end of the root aboard and shaking it, 

 when the unsuspecting crab would rush down in all haste into 

 a pail or jar held at the bottom. 



They have many enemies, not only among fish, reptiles, and 

 birds, but even some of the mammals, such as opossums and 

 monkeys, catch and devour them in large numbers. We 

 saw a beautiful Hawk, 54 bright chestnut in color, with a pale 

 creamy head and black throat, dashing at them and skil- 

 fully catching the unfortunate crabs in one outstretched 

 foot. 



Scores of other beings of still more lowly degree swarmed 

 about us, but as the tide lapped out of our little bayou, the 

 four-eyes again attracted our attention. They began to get 

 restless, swimming back and forth and shuffling over the mud, 

 until at last in desperation at the ebbing of their element, they 

 made a dash to get past us into the open water of the cano. 

 Some dived, but so buoyant are they that they can scarcely 

 stay below a second, and soon popped up on the surface again. 

 Others scrambled, rolled, and squhmed along over the ooze on 

 each side of us, many making good progress and escaping. 

 We caught several and placed them in an aquarium for study. 

 When hard pressed in deep water these curious fish progress 

 by a series of leaps up on their tail end and down a^ain, 

 up and down again, describing a scries of curves and making 

 very fast time. 



When examined closely we see that these fish have only two 

 ryes, but these are divided in such a way that there appear 

 to be double that number. There are two distinct ] .upils, one 

 elevated above the head like the eyes of a frog, the other 

 separated by a band of tissue and below the water-line. So 

 when the fish floats in its normal position at the surface the 

 upper pupils, fitted for vision in the air, watch for danger 

 above, while the lower pair keeps a submarine lookout for 

 insect food and aquatic enemies. 



