Dr. Horsfield thinks that it is an animal elaboration, perhaps a kind of secretion; but to determine its nature accurately, it should be carefully analyzed, the anatomy of the bird should be investigated, and its character and habits watched.
The kayman of the Dutch, the _boáya_ of the Malays, and the _bóyo_ or _bájul_ of the Javans, which abounds along the shores and in the principal rivers of the island, resembles more the crocodile of Egypt than that of the Ganges, or the American alligator. The character of the lacerta crocodiles, as given in the Systema Naturæ, applies to the Javan crocodile, with this difference, that in the latter the two crests of the tail coalesce towards the extremity, in which respect it agrees with that of the Ganges; but its head and jaws are broad, and rounded. In its manners, habits, and destructive qualities, it resembles the largest animals of this genus. Next to the crocodile in size is the _béwak_ of the Malays, or _menyáwak_ or _selíra_ of the Javans. It sometimes attains the length of six or seven feet, and lives near the banks of rivers and marshes. Its character agrees with those of the lacerta monitor. It is erroneously denominated the guana by Europeans. The eggs of this animal, as well as of the crocodile, are eaten by the natives, and the fat is collected for medical purposes. A small lizard, the _búnglon_ of the Javans, is erroneously called the chameleon, in consequence of the property of changing its colour. It has the specific characters of the guana, but is much smaller, seldom exceeding eighteen or twenty inches in length. There are various other lizards.
Two varieties of the turtle, _pényu_ and _pényu kombang_, are found in the seas surrounding Java. Both yield the substance called tortoise-shell, but they are seldom taken of sufficient size to render it valuable: the flesh is excellent. Another kind, of which the species is unknown, renders a thicker shell. _Kúro_ is the name of the common land-tortoise, which is found very abundantly in particular districts.
Besides the rana esculenta, green frog (_kódok íjù_ of the Javans) which is frequently eaten, and the _kódok benju_, there is the common toad, _kódok_, and the _bánkong_ and _kíntel_. The frog-fish (rana paradosa), or a variety of it, is also found on the island, and has been exhibited in the same supposed metamorphosis as in other countries. No noxious quality of any of these animals is here known.