pentine truly been formed at so many epochs, or must we view it as we do porphyry, without any reference to the surrounding rocks? Shall we rather admit only one eruption of serpentine posterior to the transition red sandstone; or shall we give to it one more ancient and anterior to the newer grey wacke, or even to the transition slate? These are questions difficult to be answered. It would be absurd to admit five eruptions of serpentine. We are of opinion, that the formation of serpentine is not so ancient as has been imagined, and will not in all probability be far from the truth, if we limit the appearance of serpentine to the great transition era, from the termination of the talco-schistose deposites, to the beginning of the independent coal formation.

We may here add, that the true relations of potstone to serpentine have not hitherto been ascertained in a satisfactory manner. It is probable that potstone bears the same relation to serpentine that schaalstein, a particular calcareous amygdaloidal trap, does to transition trap. It is well known that these last-mentioned rocks, viz. the schaalstein and transition trap in Westphalia and in Cumberland, form the transition from the slate or limestone to the trap, and even occur separately from this last rock, and are rarely brecciated. Many geologists confound it with true amygdaloid, which generally forms the upper and under parts of trap-veins, and bed-like veins and masses. The schaalstone seems to be transition rock altered by the emanation of the heat of the melted trap. If this view be correct, it could be employed, in the way of analogy, in the explanation of rocks associated with serpentine, and similarly situated, in interrupted small masses.

Observations on the Natural History of the Alligator. In a Letter to Sir WILLIAM JARDINE, Baronet, and PRIDEAUX JOHN SELBY, Esq. Вy JOHN J. AUDUBON, Esq. Member of the Wernerian Natural History Society, &c.

MY DEAR SIRS,

ONE of the most remarkable objects connected with the Natural History of the United States, that attracts the traveller's

eye, as he he ascends through the mouths of the mighty sea-like river Mississippi, is the Alligator. There, along the muddy shores, and on the large floating logs, these animals are seen either lying basking and asleep, stretched to their full length, or crossing to and fro the stream in search of food, with only the head out of water. It is here neither wild nor shy, neither is it the very dangerous animal represented by travellers. But, to give you details that probably may not be uninteresting to you, I shall take you to their more private haunts, and relate what I have experienced and seen respecting them and their habits.

In Louisiana, all our lagoons, bayous, creeks, ponds, lakes, and rivers, are well stocked with them, they are found whereever there is a sufficient quantity of water to hide them, or to furnish them with food, and they continue thus, in great numbers, as high as the mouth of the Arkansas River, extending east to North Carolina, and as far west as I have penetrated. On the Red River, before it was navigated by steam-vessels, they were so extremely abundant, that, to see hundreds at a sight along the shores, or on the immense rafts of floating or stranded timber, was quite a common occurrence, the smaller on the backs of the larger, groaning and uttering their bellowing noise, like thousands of irritated bulls about to meet in fight, but all so careless of man, that unless shot at, or positively disturbed, they remained motionless, suffering boats or canoes to pass within a few yards of them, without noticing them in the least. The shores are yet trampled by them in such a manner, that their large tracks are seen as plentiful as those of sheep in a fold. It was on that river particularly that thousands of the largest size were killed, when the mania of having either shoes, boots, or saddle-seats, made of their hides, lasted. It had become an article of trade, and many of the squatters and strolling Indians followed for a time no other business. The discovery that the skins are not sufficiently firm and close-grained, to prevent water or dampness long, put a stop to their general destruction, which had already become very apparent. The leather prepared from these skins was handsome and very pliant, exhibiting all the regular lozenges of the scales, and able to receive the highest degree of polish and finishing.

The usual motion of the alligator, when on land, is slow and

1

sluggish; it is a kind of laboured crawling, performed by moving alternately each leg, in the manner of a quadruped when walking, scarce able to keep up their weighty bodies from dragging on the earth, and leaving the track of their long tail on the mud, as if that of the keel of a small vessel. Thus they emerge from the water, and go about the shores and the woods, or the fields, in search of food, or of a different place of abode, or one of safety to deposit their eggs. If, at such times, when at all distant from the water, an enemy is perceived by them, they droop and lie flat, with their nose on the ground, watching the intruder's movements with their eyes, which are able to move considerably round, without affecting the position of the head. Should a man then approach them, they do not attempt either to make away or attack, but merely raise their body from the ground for an instant, swelling themselves, and issuing a dull blowing sound, not unlike that of a blacksmith's bellows. Not the least danger need be apprehended; then you either kill them with ease or leave them. But, to give you a better idea of the slowness of their movements and progress of travels on land, when arrived at a large size, say 12 to 15 feet, believe me when I tell you, that, having found one in the morning 50 yards from a lake going to another in sight, I have left him unmolested, hunted through the surrounding swamps all the day, and met the same alligator within 500 yards of the spot, when returning to my camp at dusk. On this account they usually travel during the night, they being then less likely to be disturbed, and having a better chance to surprise a litter of pigs, or of landtortoises, for prey.

The power of the alligator is in his great strength; and the chief means of his attack or defence is his large tail, so well contrived by nature to supply his wants, or guard him from danger, that it reaches, when curved into half a circle, his enormous mouth. Woe be to him who goes within the reach of this tremendous thrashing instrument, for no matter how strong or muscular; if human, he must suffer greatly, if he if he escapes with life. The monster, as he strikes with this, forces all objects within the circle towards his jaws, which, as the tail makes a mo

tion, are open to their full stretch, thrown a little sidewise, to

receive the object, and, like battering-rams, to bruise it shockingly in a moment.

The alligator, when after prey in the water, or at its edge, swims so slowly towards it, as not to ruffle the water. It approaches the object sidewise, body and head all concealed, till sure of his stroke; then, with a tremendous blow, as 'quick as thought, the object is secured, as I described before.

When alligators are fishing, the flapping of their tails about the water may be heard at half a mile; but, to describe this in a more graphic way, suffer me to take you along with me, in one of my hunting excursions, accompanied by friends and negroes. In the immediate neighbourhood of Bayou Sarah, on the Mississippi, are extensive shallow lakes and morasses, that are yearly overflowed by the dreadful floods of that river, and supplied with myriads of fishes of many kinds, amongst which trouts are most abundant, white-perch, cat-fish, and alligatorgars, or devil-fish. Thither, in the early part of autumn, when the heat of a southern sun has exhaled much of the water, the squatter, the planter, the hunter, all go in search of sport. The lakes are then about 2 feet deep, having a fine sandy bottom; frequently much grass grows in them, bearing crops of seeds, for which multitudes of water-fowls resort to those places. The edges of these lakes are deep swamps, muddy for some distance, overgrown with heavy large timber, principally cypress, hung with Spanish beard, and tangled with different vines, creeping plants and cane, so as to render them almost dark during the day, and very difficult to the hunter's progress. Here and there in the lakes are small islands, with clusters of the same trees, on which flocks of snake-birds, wood-ducks, and different species of herons, build their nests. Fishing-lines, guns, and rifles, some salt and some water, are all the hunters take. Two negroes precede them,-the woods are crossed,-the scampering deer is seen,—the racoon and the opossum cross before you, the black, the grey, and the fox squirrel, are heard barking, here on a tree close at hand, is seen an old male pursuing intensely a younger one; he seizes it, they fight desperately, but the older attains his end, vincit, castratque juniorem. (Now, my dear Sirs, if this is not mental power illustrated, what shall we call it)? As you proceed farther on, the hunk

hunk of the lesser ibis is heard from different parts, as they rise from the puddles that supply them with cray-fishes. At last the opening of the lake is seen; it has now become necessary to drag one's-self along through the deep mud, making the best of the way, with the head bent, through the small brushy growth, caring about nought but the lock of your gun. The long narrow Indian canoe kept to hunt those lakes, and taken into them during the fresh, is soon launched, and the party seated in the bottom is paddled or poled in search of water-game. There, at a sight, hundreds of alligators are seen dispersed over all the lake, their head, and all the upper part of the body, floating like a log, and, in many instances, so resembling one, that it requires to be accustomed to see them to know the distinction. Millions of the large wood-ibis are seen wading through the water, mudding it up, and striking deadly blows with their bills on the fish within. Here are a hoard of blue herons,-the sandhill-crane rises with his hoarse note,- the snake-birds are perched here and there on the dead timber of the trees,-the cormorants are fishing,-buzzards and carion-crows exhibit a mourning train, patiently waiting for the water to dry and leave food for them, and far in the horizon the eagle overtakes a devoted wood-duck, singled from the clouded flocks that have been bred there. It is then that you see and hear the alligator at his work, -each lake has a spot deeper than the rest, rendered so by those animals who work at it, and always situate at the lower end of the lake near the connecting bayous, that, as drainers, pass through all those lakes, and discharge sometimes many miles below where the water had made its entrance above, thereby ensuring to themselves water as long as any will remain. This is called by the hunters the Alligator's Hole. You see them there lying close together. The fish that are already dying by thousands, through the insufferable heat and stench of the water, and the wounds of the different winged enemies constantly in pursuit of them, resort to the Alligator's Hole to receive refreshment, with a hope of finding security also, and follow down the little currents flowing through the connecting sluices: but, no! for, as the water recedes in the lake, they are here confined. The alligators thrash them and devour them whenever they feel hungry, while the ibis destroys all that make towards