The tree-ferns--the chamaerops, the pandanus, the araucarias--are modern representatives of past types. The former is a palm belonging to the ancient vegetable world, but having its representative in our days. The modern chamaerops, with its fan-like leaves spreading on one level, stands, with respect to its structure, lower than the palms with pinnate leaves, which belong almost exclusively to our geological age, and have numerous leaflets ranging along either side of a central axis. The young palms, while their elders tower fifty feet above them, are often not more than two inches high; and to whatever genus they may belong, invariably resemble the chamaerops,--having their leaves extending fan-like on one plane, instead of being scattered along a central axis, as in the adult tree. The infant palm is, in fact, the mature chamaerops in miniature; showing that among plants, as among animals--at least in some instances--there is a correspondence between the youngest stages of growth in the higher species of a given type, and the earliest introduction of that type on earth. More gregarious in their habits than most other palms are the urucuri palms--Attalea excelsa--groves of which beautify the higher lands, and grow in vast numbers under the crowns of the more lofty ordinary forest-trees; their smooth columnar stems being generally fifty feet in height, while their broad, finely pinnated leaves, interlocking above, form arches and woven canopies of elegant and diversified shapes. The fruit, in size and shape like the date, has a pleasant flavoured juicy pulp, and falls to the ground when ripe. PART THREE, CHAPTER SEVENTEEN. THE WONDERS OF THE WATERS. THE MANATEE, OR COW-FISH. To maintain the claim of its ocean character, the Amazon possesses that huge, whale-like creature the manatee, or cow-fish, called by the Brazilians _peixe boi_, or _vacca marina_. It is generally about seven or eight feet long, though it attains a length of ten feet or more, and nine feet and upwards in girth. On the upper part the body is perfectly smooth, and of a lead colour. It tapers off towards the tail, which is flat, horizontal, and semicircular, without any appearance of hind-limbs. The head is in reality small, and the neck undistinguishable; though it has an enormous mouth, with fleshy lips like those of a huge cow, with an ugly countenance. On the lips are stiff bristles, while a few hairs only are scattered over the body. Just behind the head are two powerful oval fins, beneath which, in the female, are the breasts. The ears are very minute holes, and the eyes are extremely small. The skin of the back is fully an inch thick; and beneath it is a layer of fat, also an inch or more in thickness. The fins of the fore-limbs consist of bones exactly corresponding to those of the human arm, with five fingers at the extremity--every joint distinct, although completely encased in its thick inflexible skin.