THIS animal is the first example of some Marsupial beasts which are separated into a sub-order, because, in addition to the marsupial bones, there are some internal points of construction which are more bird- and lizard-like than those of the Kangaroo tribes. It contains animals which are the lowest of the Mammalian class, and are found only in the Australian natural history province. The Porcupine Ant-eater, as its name implies, has somewhat the shape of a Hedgehog or Porcupine, and it is fond of burrowing with its peculiar limbs, as well as of eating Ants with the assistance of its long tongue. But its internal anatomy and the construction of the skeleton differ from those of the true Ant-eaters, which belong to the order Edentata. It was called Ant-eater by its first describer (Shaw) in 1792, but a few years afterwards it was decided to belong to the same group as an animal about to be described—the Duck-billed Platypus, or Water Mole—and Cuvier, whilst believing that they both belonged to a peculiar order, separated this false Ant-eater from the Water Mole as a species and genus. He called this Hedgehog-like creature Echidna, from the presence of a spur on the heel, which is perforated, and which was erroneously supposed to be poisonous, like the fang of a Viper (Ἔχιδνα). The correct name is the Long-spined Echidna, or the Porcupine Echidna (Echidna hystrix).
PELVIC ARCH OF THE ECHIDNA.
(a a) Marsupial Bones.
The creature greatly resembles a Hedgehog with a very long snout, at first sight, but a slight examination will show that it differs much from the insect-eating and spiny little Hystrix. The Echidna is about a foot in length, and the upper part of its short body is covered with strong spines, and the rest is hairy, the front of the head, and the long, slender, and tapering snout being naked. The legs are short and strong, and the five toes of the fore leg have large and strong claws. This is in order to permit the creature to bury itself in sand and soft earth quickly, and this operation is assisted by a broad and rounded nail on the inner toe of the hind foot and by large claws on the other toes, and especially by a long nail to the second toe. A very long and flexible tongue enables the creature to catch prey. There are no teeth. The skull, when the skin and flesh have been removed, has a very pear-like appearance. It is a great burrower, and manages to get out of the way of observers as soon as is possible, for working actively with its strong limbs and claws, it pokes its snout into the earth and soon gets out of view. Ants are its favourite food, and they are captured in the same way as by the Great Ant-eaters belonging to the Edentata: for in both there is a long slimy tongue, which can be poked far out of the mouth into Ants’ nests. The saliva required to make the tongue sticky comes from large glands under the lower jaw from the ear on to the fore part of the chest. When the Ants have collected on the sticky tongue it is taken into the mouth, and they are swallowed. The absence of teeth is made up by the presence of horny spines on the palate and tongue, which look backwards, and these crush and direct the food to the throat. It is an apathetic and stupid animal, and usually tries to get out of the light, and it will lie and roll itself up, but not so successfully as a Hedgehog. One of the first which was seen was attacked by the Dogs of two of the travellers, Bass and Flinders, whose names are so familiar from places having been named after them in Australia. The Dogs did not come off victorious, for the new animal burrowed in the loose sand, but not head foremost; it sank itself directly downwards, and left its prickly back just on a level with the surface.
An Echidna was watched, so that the manner in which it could use its tongue was observed. Ants could not be had, but a diet of chopped-up eggs, liver, and meat was readily received, and it was noticed that the tongue was used in the same manner as that of the Chameleon, by simple protrusion and bringing in, and also as a mower moves his scythe, it being curved sideways, and the food swept into the mouth. The Echidna is fond of water and milk, which are licked up by a rapid putting out and drawing in of the long tongue.
PORCUPINE ECHIDNA. (After Gervais.)
Gerard Krefft says that they are usually found in mountain ranges, and among rocks in the Lower Murray district. He failed to feed them on Ants and their eggs. On hen’s eggs they fed for a time, and liked bread-and-milk. He has reason to believe that they live on grass also, as those whose stomachs and intestines he examined had fed on herbs and grasses. The spur on the heel is not used as a weapon of offence.
It inhabits Australia, and has been found as far north as the Bellenden Plains, Queensland, about 18° south latitude. A specimen has also been captured at Cape York, and others at Plain Creek, Queensland. It is not found in Van Diemen’s Land.
With regard to the anatomy of the Echidna, it may be said that the long muzzle and the very slender lower jaw give the skull a bird-like look which is increased by the swollen and ball shape of the brain-case. The bones of the skull remain imperfectly united for some time, and then they are united by plain lines of junction, and not by jagged sutures. The shoulder and the bones of the upper part of the chest resemble those of the Water Mole, and will be noticed in its description. The brain of the Echidna weighs about one-fiftieth of the whole body, and the hemispheres do not conceal the cerebellum. There are three convolutions behind, and in front of them is a large one bent on itself, and on its outside are some oblique folds. The sense of smell, evidently acute in the Echidna, is assisted by a large development of the olfactory lobes of the brain and their nerves.