I had been travelling for about an hour, trying to locate the source of the Santa Rita, and winning every inch of ground by hacking and slashing with the machete, when I was startled by a most fearful scream, which seemed to come from somewhere immediately behind me. To say that my blood "froze in my veins," even in this tropical climate, would be but a poor and inadequate figure of speech to describe my feelings. I had heard of the treachery of the San Blas Indians who inhabit the country to the eastward, and my first thought was of them. Turning round and looking back anxiously over the trail I had just made, I saw a great commotion taking place among the vines, dead leaves, and decaying branches which carpeted the ground, and the blood-curdling screams I had heard rang out again and again. For what seemed hours to me, but were really only seconds, I could not comprehend what was transpiring so close to me, and what kind of creature was giving utterance to such agonizing cries. At length, however, venturing a little nearer, I discovered it to be a "tiger," or, properly speaking, a jaguar or American leopard, and it was writhing in the coils of an enormous boa-constrictor. The great snake appeared to have the side of the jaguar's head in its mouth, and a coil or two of its body around the neck of the beast, which was making frantic efforts to regain its liberty. The snake had its tail coiled round a small ebony tree about a foot in diameter, and whenever the hapless jaguar relaxed its efforts the serpent would swiftly release itself from the tree and make an attempt to get another coil around the body of its opponent. I stood there fascinated with horror, and yet forgetting my fear in the interest I was taking in this terrible fight between beast and reptile. Presently the snake, with an incomprehensibly quick movement--in fact, almost too quick for the eye to follow--succeeded in getting two more coils around the body of the jaguar, but not without receiving several severe lacerations from the formidable claws of its victim. Then letting go the jaguar's head, where it seemed to have a firm hold, the boa-constrictor raised its head, seemingly in triumph, and, with its tail still wrapped round the tree, lifted the body of the jaguar up in the air. I heard the bones crack under the fearful strain, and with one awful, despairing scream the jaguar fell back--dead!