or in bad health will seriously menace his life.  In the marsh we were continually wading, now up to our knees, now up to our hips.  Twice we came to long bayous so deep that we had to swim them, holding our rifles above water in our right hands.  The floating masses of marsh grass, and the slimy stems of the water-plants, doubled our work as we swam, cumbered by our clothing and boots and holding our rifles aloft.  One result of the swim, by the way, was that my watch, a veteran of Cuba and Africa, came to an indignant halt.  Then on we went, hampered by the weight of our drenched clothes while our soggy boots squelched as we walked.  There was no breeze.  In the undimmed sky the sun stood almost overhead.  The heat beat on us in waves.  By noon I could only go forward at a slow walk, and two of the party were worse off than I was.  Kermit, with the dogs and two camaradas close behind him, disappeared across the marshes at a trot.  At last, when he was out of sight, and it was obviously useless to follow him, the rest of us turned back toward the boat.  The two exhausted members of the party gave out, and we left them under a tree.  Colonel Rondon and Lieutenant Rogaciano were not much tired; I was somewhat tired, but was perfectly able to go for several hours more if I did not try to go too fast; and we three walked on to the river, reaching it about half past four, after eleven hours’ stiff walking with nothing to eat.  We were soon on the boat.  A relief party went back for the two men under the tree, and soon after it reached them Kermit also turned up with his hounds and his camaradas trailing wearily behind him.  He had followed the jaguar trail until the dogs were so tired that even after he had bathed them, and then held their noses in the fresh footprints, they would pay no heed to the scent.  A hunter of scientific tastes, a hunter-naturalist, or even an outdoors naturalist, or faunal naturalist interested in big mammals, with a pack of hounds such as those with which Paul Rainey hunted lion and leopard in Africa, or such a pack as the packs of Johnny Goff and Jake Borah with which I hunted cougar, lynx, and bear in the Rockies, or such packs as those of the Mississippi and Louisiana planters with whom I have hunted bear, wild-cat, and deer in the cane-brakes of the lower Mississippi, would not only enjoy fine hunting in these vast marshes of the upper Paraguay, but would also do work of real scientific value as regards all the big cats.

Only a limited number of the naturalists who have worked in the tropics have had any experience with the big beasts whose life-histories possess such peculiar interest.  Of all the biologists who have seriously studied the South American fauna on the ground, Bates probably rendered most service; but he hardly seems even to have seen the animals with which the hunter is fairly familiar.  His interests, and those of the other biologists of his kind, lay in other directions.  In consequence, in treating of the life-histories of the very interesting