The leaf of the great water lily of the Amazon river (Victoria regia) has been known to grow to the diameter of 6 feet, and yet the pulpy tissue which makes up its surface is so delicate and tender, that a straw held 6 inches above and dropped perpendicularly upon it would readily pass through it. This vast area of a substance as tender as that of a blanched lettuce is borne between and over a series of singularly contrived nerves and veins, some of which resemble arched ribs, and in order that the leaf may float they are rendered porous by large interstices; they are armed with fierce prickles to ward off aquatic animals which might injure the foliage by approaching from beneath. Such an expanded surface has been found capable of sustaining a weight of more than 70 pounds if by some mechanical contrivance the pressure is equally distributed.