Another fact will soon force itself on your attention, unless you wish to tumble down and get wet up to your knees.  The soil is furrowed everywhere by holes; by graves, some two or three feet wide and deep, and of uncertain length and shape, often wandering about for thirty or forty feet, and running confusedly into each other.  They are not the work of man, nor of an animal; for no earth seems to have been thrown out of them.  In the bottom of the dry graves you sometimes see a decaying root:  but most of them just now are full of water, and of tiny fish also, who burrow in the mud and sleep during the dry season, to come out and swim during the wet.  These graves are, some of them, plainly quite new.  Some, again, are very old; for trees of all sizes are growing in them and over them.

What makes them?  A question not easily answered.  But the shrewdest foresters say that they have held the roots of trees now dead.  Either the tree has fallen and torn its roots out of the ground, or the roots and stumps have rotted in their place, and the soil above them has fallen in.

But they must decay very quickly, these roots, to leave their quite fresh graves thus empty:  and—­now one thinks of it—­how few fallen trees, or even dead sticks, there are about.  An English wood, if left to itself, would be cumbered with fallen timber; and one has heard of forests in North America, through which it is all but impossible to make way, so high are piled up, among the still-growing trees, dead logs in every stage of decay.  Such a sight may be seen in Europe, among the high Silver-fir forests of the Pyrenees.  How is it not so here?  How indeed?  And how comes it—­if you will look again—­that there are few or no fallen leaves, and actually no leaf-mould?  In an English wood there would be a foot—­ perhaps two feet—­of black soil, renewed by every autumn leaf fall.  Two feet?  One has heard often enough of bison-hunting in Himalayan forests among Deodaras one hundred and fifty feet high, and scarlet Rhododendrons thirty feet high, growing in fifteen or twenty feet of leaf-and-timber mould.  And here, in a forest equally ancient, every plant is growing out of the bare yellow loam, as it might in a well-hoed garden bed.  Is it not strange?

Most strange; till you remember where you are—­in one of Nature’s hottest and dampest laboratories.  Nearly eighty inches of yearly rain and more than eighty degrees of perpetual heat make swift work with vegetable fibre, which, in our cold and sluggard clime, would curdle into leaf-mould, perhaps into peat.  Far to the north, in poor old Ireland, and far to the south, in Patagonia, begin the zones of peat, where dead vegetable fibre, its treasures of light and heat locked up, lies all but useless age after age.  But this is the zone of illimitable sun-force, which destroys as swiftly as it generates, and generates again as swiftly as it destroys.  Here, when the forest giant falls, as some tell me that they have heard him fall, on silent nights, when the cracking of the roots below and the lianes aloft rattles like musketry through the woods, till the great trunk comes down, with a boom as of a heavy gun, re-echoing on from mountain-side to mountain-side; then—­