Natural History: Mammalia/Monotremata
ORDER II. MONOTREMATA.
(Beaked Marsupials.)
We have now arrived at creatures of so strange and anomalous structure, as to have given rise to much discussion among men of science concerning their true affinities, and the Class of animals to which they properly belonged. When the most singular of these animals was first received in England, the union of a beak closely resembling that of some Ducks, with the body of a fur-clothed quadruped, was so startling a novelty, that the utmost suspicion was roused of its genuineness; and though repeated and careful examinations of the specimen were instituted, even to the maceration of the suspected organs in water, it was not until other individuals were sent from New Holland, that zoologists were satisfied that no clever artifice had been employed in "making up" the specimen.
Recent investigations have proved that the peculiar organization of these animals is not confined to their external form; and if more extended inquiries have familiarized us with their structure, and so diminished our wonder at its unwonted combinations, they have brought more fully to view, in many anatomical particulars, that these creatures are indeed unique, and possess peculiarities which broadly separate them from all other known animals.
From the nature of these peculiarities, they cannot be enumerated in a treatise like the present: suffice it to observe, that in the form of the skull, in the construction of the shoulder, and of the breast-bone, but particularly in the whole reproductive system of organs, the Monotremata present a manifest departure from a mammalian type, and a correspondent approach to that of the oviparous Vertebrata, tending to the Reptiles, more than to the Birds.
At the same time the preponderance of their organization shews, that notwithstanding their anomalies, they are truly Mammalia; and though they do not possess any external trace of an abdominal pouch, the presence of the marsupial bones in the skeleton, and many other details of their anatomy, sufficiently declare that their nearest affinities are with the Marsupialia, of which they constitute the lowest and most aberrant type.
In these singular animals there are no true teeth, though one genus possesses horny substances in the jaw which represent those organs; the muzzle is produced into a long and flat beak, more or less resembling that of a duck; the eyes are small; the ears are merely minute orifices, destitute of external conch; the limbs are short and strong, adapted for digging; the feet have each five toes, furnished with stout claws, and on the hind feet is a sort of sharp spur, which has been supposed, but as it seems erroneously, to be a weapon of defence.
The order contains two genera, Echidna and Ornithorhynchus; both of which are confined to New Holland and Van Diemen's Land. Genus Echidna. (Cuv.)
In some respects the muzzle of this animal resembles that of the Ant-eaters, being much elongated, slender, terminated by a small mouth, and inclosing a long extensile tongue. It is, however, much more beak-like: immediately in front of the eyes, the muzzle, which is rather depressed, is suddenly contracted, and thence tapers gradually to the tip. The skin of this beak is thick and destitute of hair. It has no teeth, but the palate is armed with many rows of small spines directed backwards. The limbs are very large and robust, and formed for burrowing, or for opening ant-nests, being furnished with very long and strong nails. "The inner toe of the hind-foot," says Mr. Waterhouse, "is very short and thick, and furnished with a short, broad, and rounded nail, and appears to be slightly opposible; the toe next the inner one is the largest, though still short and strong, and is furnished with an enormously long nail, one inch and four lines in length; this nail is slightly curved, and appears, when viewed in front, to be nearly cylindrical, but its under surface is concave. The nail of the central toe resembles the last, but is rather smaller, and that of the outer toe is the shortest, being not more than a quarter of an inch in length. The Echidna being a burrowing animal, it would appear that the broad, strong claws of the fore-feet are for digging out the earth, and the large hollow claws of the hind-feet are to enable the animal to cast away the loose soil; and to accomplish this, the foot is twisted in such a manner that the sides of these claws lie on the ground, and the concave part is behind."
The upper surface of the body, and of the short tuberculous tail, is covered by a compact mass of stout and strong spines, intermingled with stiff bristly hairs. For the most part they are directed backwards, but towards the middle of the back their points cross each other; but when alarmed the animal has the power of rolling itself up like the hedgehog, when the strong spines project in all directions as from a common centre.
ECHIDNA.
There appears to be but a single species (Echidna aculeata, Shaw.) which is found in New South Wales and in Van Diemen's Land. A second species (E. setosa, Desm.) has indeed been described, which is said to be distinguished by having fewer and shorter spines on the body, and these are imbedded almost to the points in a dense, woolly, brown fur;—but these diversities are more generally considered as seasonal variations.
The length of the Echidna (the Hedgehog of the colonists), is about one foot; the colour of the spines is a dirty yellowish-white, with blackish tips; that of the stiff hair with which the rest of the body and limbs are clothed is a blackish-brown. Its food consists of ants with their larvæ and pupæ, which, like the true Ant-eaters, it takes by means of a long worm-like tongue, which it can protrude to a great distance, and which is always covered with an adhesive secretion. Its powers of burrowing are very great. Messrs. Bass and Flinders state that their dogs, having found one of these "Porcupine Ant-eaters," could make no impression on the animal, which escaped by burrowing in the loose sand, not head-foremost, but by sinking itself directly downwards, and thus presenting nothing but its prickly back to its assailants. And according to Mr. G. Bennett, it will even work its way under a pretty strong pavement or base of a wall, removing the stones with its claws. During these exertions its body is stretched or lengthened to an uncommon degree, and appears very different from the short plump aspect, which it bears in its undisturbed state.
Messrs. Quoy and Gaimard, who procured one of these animals in Van Diemen's Land, have given an account of its manners while in their possession. They describe it as stupid and listless; for a month after its capture, it refused all sustenance, from which it did not appear to suffer, though it became very meagre. It sought the darkest places, shunning the light of day; or remained with its head crouched between its fore-legs; in which position it presented at all points a mass of spines. They deny to it, however, the power of rolling itself up into a ball. Notwithstanding its ordinary apathy, it appeared to appreciate the sweets of liberty, making incessant efforts to escape from its cage. The readiness with which it burrowed was surprising: being placed on a large box of earth, containing plants, it penetrated to the very bottom in less than two minutes: the muzzle, though very sensitive, assisted in the performance of this operation.
After its first abstinence, which lasted for a month, it began to eat; it was fed with a mixture of sugar, flour, and water, of which it consumed nearly half a glass every day. It at length died, in consequence, as was supposed, of its too frequent ablutions; but these naturalists think that the animal may be easily brought to Europe; particularly as it becomes torpid during the prevalence of cold weather.
The same opinion is expressed by Lieutenant Breton, notwithstanding the failure of his own attempt, by the death of an individual which he was endeavouring to bring alive to England. In a communication made by him to the Zoological Society, and published in their Proceedings for 1834, that gentleman has added to our information some interesting notes of this singular animal. Previously to embarkation, this individual was fed on ant-eggs and milk, and when on board its diet was egg, chopped small, with liver and meat. It drank much water. Its mode of eating was very curious, the tongue being used at some times in the manner of that of the chameleon, and at others, in that in which a mower uses his scythe, the tongue being curved laterally, and the food, as it were, swept into the mouth; there seemed to be an adhesive substance on the tongue, by which the food was drawn in. The animal died suddenly, off Cape Horn, while the vessel was amidst the ice; perhaps in consequence of the cold, but not improbably on account of the eggs, with which it was fed, being extremely bad.
This individual was captured on the Blue Mountains; it is become uncommon in the inhabited parts of New South Wales. Mr. Bennett states, that it inhabits the mountain ranges of Australia; and that it brings forth its young in December. It is believed to be nocturnal in its habits. Its flesh is eaten by the natives, and is said to resemble in flavour that of sucking-pig.
Genus Ornithorhynchus. (Blum.)
The impression which would be produced by the sight of this most singular of all quadrupeds, on one who had never heard of it, would be, that the beak of a shoveller-duck had been artificially fastened on the front of the head of a small otter. The beak is flat, broader at the tip than at the base, and covered by a thick leathery skin; between the base and the head, this skin projects in the form of a loose flap from each mandible, which probably serves to protect the eyes from the mud, in which the animal is perpetually dabbling, in search of food. The skin on the sides of the lower mandible is indented with numerous transverse furrows. There are no true teeth; but at the back of each mandible, in the ordinary place of molars, are two horny appendages, resembling teeth, but without roots, which are of a somewhat square form, and have a broad, uneven surface, calculated for crushing rather than grinding. Beneath the skin of the face are capacious cheek-pouches, for the carrying of food. The eyes are bright, but very small, and situated high on the forehead. The ears are mere orifices, easily discernible during life, being opened and closed by the will of the animal, but scarcely to be perceived in dead specimens.
On both the fore and hind-feet are five well-developed toes, all armed with long, curved, and pointed claws. They are all connected by a leathery web, which in the fore-feet extends considerably beyond the tips of the claws, presenting a broad and powerful oar when in the water, but folded back when the animal is engaged in digging the earth. On the hind-feet the web reaches only to the extremities of the toes. The hind-feet are armed also with a stout, sharp, moveable spur, which was formerly regarded as highly poisonous; the experiments of Mr. Bennett, however, prove that no use is made of it in defence, and that scratches produced accidentally by it, are followed by no ill effects. In the male alone is this spur well developed.
The body is somewhat flattened, bearing some resemblance to that of a small otter; the tail is broad and depressed.
Two species have been described under the names of Ornithorhynchus fuscus, and O. rufus; the distinctions, however, are very slight, the latter having the fur softer, and of a redder tint than the former; and naturalists are not yet agreed, whether these are to be regarded as constituting differences of species, or but of varieties. We shall, therefore, speak of the Ornithorhynchus, without distinguishing.
Mr. Waterhouse has described some curious peculiarities in the structure of the fur. "The fur is short, very dense, and rather soft to the touch; and combines the properties usually found in that of an aquatic animal, and that of one whose habit is to burrow: it will readily expel both the water and the dust; it is composed of hairs of two kinds, the one forming a remarkably fine and dense fur, resembling that of the mole; the other hairs are longer, have the basal half fine like the under fur, but the apical, exposed half of each hair is dilated and flat, bent at an angle with the basal portion, and is very glossy, resembling the hairs of the seal. In these longer hairs, being thin at the base, bent near the middle, and expanded and stiff at the tip, we see a beautiful provision suited to the habits of the animal. When in the water, the flat points become closely applied together, and afford a waterproof covering to the fine under fur; and when in its under-ground galleries, their peculiar texture and bent form permits the animal to move either backwards or forwards without inconvenience, and without exposing the skin to the dirt."[1]
A full-grown Ornithorhynchus is about two feet in length, including the beak and the tail; of which the former measures two inches and a half, and the latter five inches. The general colour is deep brown; (rich red brown in some specimens;) the under parts much paler; a white spot is situated in front of each eye. It is found both in New South Wales and Van Diemen's Land.
ORNITHORHYNCHUS.
Our acquaintance with the economy of the Ornithorhynchus in a state of nature, we owe entirely to the researches of Mr. George Bennett; and we willingly close this volume with some extracts from his valuable communication on this subject to the Zoological Society; the more copious, as the details of the habits of an animal so anomalous cannot but be of singular interest.
"The Water-Moles (as these animals are called by the colonists) chiefly frequent the open and tranquil parts of the stream covered with aquatic plants, where the steep and shaded banks afford excellent situations for the excavation of their burrows. Such expanses of water are by the colonists called ponds. The animals may be readily recognized by their dark bodies just seen level with the surface, above which the head is slightly raised, and by the circles made in the water around them by their paddling action. On the slightest alarm they instantly disappear; and, indeed, they seldom remain longer on the surface than one or two minutes, but dive head-foremost, with an audible splash, reappearing, if not alarmed, a short distance from the spot at which they dived. Their action is so rapid, and their sense of danger so lively, that the mere act of levelling the gun is sufficient to cause their instant disappearance; and it is, consequently, only by watching them when diving, and levelling the piece in a direction towards the spot at which they seem likely to reappear that a fair shot at them can be obtained. A near shot is absolutely requisite; and when wounded they usually sink immediately, but quickly reappear on the surface."
Mr. Bennett has described the burrows of these interesting animals, several of which he examined; they are constructed in the bank of the river, the entrance being above the surface, usually concealed among the herbage. Though the mouth is large, it quickly diminishes to a passage barely admitting the animal, but running along through the earth in a serpentine direction, sometimes to the distance of fifty feet, and terminating in a small chamber. Here the nest is placed, consisting of dried grass and weeds.After having traced such a burrow "for the distance of ten feet, and having just delved down upon it so as to perceive it still continuing its course up the bank, the beak and head of a Water Mole were seen protruding for an instant from the upper part, as if it had been disturbed from its repose, and had come down to see what we were about with its habitation. It only remained for an instant; for as soon as it beheld us . . . . it immediately turned up to take refuge in that
BURROW OF ORNITHORHYNCHUS.
part of the burrow which yet remained unexplored. In turning round, however, it was seized by the hind-leg and dragged out. The animal appeared very much alarmed when it was hauled out of its subterraneous dwelling; . . . . it uttered no sound, nor did it attempt to bite; and proved to be a full-grown female. When I held the unfortunate Ornithorhynchus in my hands its bright little eyes glistened, and the orifices of the ears were expanded and contracted alternately, as if eager to catch the slightest sound, while its heart palpitated violently with fear and anxiety."
The female thus taken from the burrow was placed in a cask with water, mud, and grass, where it soon became tranquil, and reconciled to its captivity. The next morning, tying a long cord to its leg, Mr. Bennett roused it, and placed it on the bank of the river in order to indulge it with a bathe; and a similar indulgence was granted to it on the next day. On these occasions "it was exceedingly lively, swam in the centre of the stream, and appeared in excellent health and spirits. The water at one part of the river being very clear, I saw its motions distinctly under the water. On diving it sank speedily to the bottom, swam there for a short distance, and then rose again to the surface; it ranged the banks, guiding itself in its progress according to the impressions received by the mandibles, which appeared to me to be used as very delicate organs of touch. It seemed to feed well; for whenever it inserted its beak into the mud it evidently procured some food from thence, as on raising the head, after withdrawing the beak, the mandibles were seen in lateral motion, as is usual when the animal masticates. Although several insects were basking and fluttering about the surface, close to it, no attempt was made to capture them . . . . After feeding it would lie sometimes on the grassy bank, and at others partly in and partly out of the water, combing and cleaning its coat, as usual, with the claws of the hind-feet. After permitting it to swim, feed, and clean itself for an hour, it was replaced, although with great reluctance on its own part, in its box; it did not, however, as before, betake itself to repose, but commenced and continued a scratching on the sides of the box."
This individual managed to make her escape from confinement; but Mr. Bennett subsequently took two half-grown young ones from a burrow, and captured a very exhausted female, which he conjectured to be their mother. The latter survived but a few days, but the young remained in his possession upwards of a month. The details of the manners of this little family in their captivity are very amusing. Mr. Bennett observes of them, "The young sleep in various postures; sometimes in an extended position; and often rolled up, like a hedgehog, in the form of a ball. They formed an interesting group, lying in various attitudes in the box in which I had placed them, and seeming happy and content. Thus, for instance, one lies curled up like a dog, keeping its back warm with the flattened tail, which is brought over it; while the other lies stretched on its back, the head resting, by way of a pillow, on the body of the old one, which lies on its side, with the back resting against the box; the delicate beak, and smooth, clean fur of the young, contrasting with the rougher and dirtier appearance of the older one: all fast asleep . . . . One evening both the young came out about dusk, and went as usual, and ate food from the saucer, and then commenced playing with one another, like two puppies, attacking with their mandibles, and raising their fore-paws against each other. In the struggle one would get thrust down, and at the moment when the spectator would expect it to rise again and renew the combat, it would commence scratching itself, its antagonist looking on, and waiting for the sport to be renewed. When running they are exceedingly animated; their little eyes glisten; and the orifices of their ears contract and dilate with rapidity; if taken into the hands at this time for examination they struggle violently to escape; and their loose integuments make it difficult to retain them. Their eyes being placed so high on the head, they do not see objects well in a straight line, and consequently run against everything in the room during their perambulations, spreading confusion among all the light and readily-overturnable articles . . . Sometimes I have been able to enter into play with them by scratching and tickling them with my finger; they seemed to enjoy it exceedingly, opening their mandibles, and biting playfully at the finger, and moving about like puppies indulged with similar treatment. As well as combing their fur to clean it when wet, I have also seen them peck at it with their beak (if the term may be allowed) as a duck would clean its feathers. When I placed them in a pan of deep water they were eager to get out after being there for only a short time; but when the water was shallow, with a turf of grass in one corner, they enjoyed it exceedingly. They would sport together, attacking one another with their mandibles, and roll over in the water in the midst of their gambols, and would afterwards retire, when tired, to the turf, where they would lie, combing themselves. They appeared to be in a great measure nocturnal, preferring the twilight to the bright glare of day."
The Ornithorhynchus has never yet been brought alive to Europe; but these and similar accounts indicate that it may yet be hoped for; as it seems no insuperable difficulty would occur in providing them with food on the voyage. Mr. Bennett fed his young captives on soaked bread, chopped egg, and meat minced very small.
- ↑ Nat. Lib. Marsupialia, 311.
INDEX.
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