Search just our sites by using our customised search engine

Unique Cottages | Electric Scotland's Classified Directory

Click here to get a Printer Friendly PageSmiley

Our Australian Cousins
Chapter X


The marsupial plague—Young of the marsupiata horn—What is a marsupial?—Able account by a "Bush Naturalist."

One of the most extraordinary phenomena of Australian animal life has been the tremendous increase in numbers, during late years, of the kangaroos and other kindred marsupials, in the western interior plains of Queensland. At the period of my visit, at which we have now arrived, the evil had become one of such enormous magnitude, that the value of station property had actually deteriorated. Legislation was cried for, on the subject. The squatters were almost powerless to stem the overwhelming tide of animal life that cropped bare every leaf and vestige of grass, and in some places the "marsupial plague," as it is called, had threatened altogether to oust the sheep and cattle from the runs, and, by eating up the whole of the scanty pasture, leave nought but barren rock and worthless weeds for the subsistence of the flocks and herds. The newspapers had been full of plans, suggestions, and disquisitions on the subject, some more or less practical, others wholly visionary. Fencing-in had been tried, but was too expensive. Hunting with dogs was found quite inadequate to cope with the evil. Some contended that the destruction of natives, and the wild native dog, and the stoppage of destructive bush fires, had done much to allow the animals to increase; but from whatever cause, the plague was becoming a gigantic evil, and threatened to interfere most seriously, if not to do away entirely, with the wool industry. On one run,, for instance, in the Stanthorpe district, it was computed that there were fully 60,000 head of marsupials, and as every one of these will eat as much grass as a sheep, the magnitude of the evil can be seen at a glance. Peak Downs' station, a well-known Queensland run, had been bought by the present owner some years ago with 40,000 head of sheep, and already at the time of my visit, more than that number of marsupials, had been destroyed by the owner.

I have made various observations, and had come independently to a conclusion of my own on one of the most disputed points in connexion with the marsupial tribe. But I have found in the Queenslander, that admirably conducted paper, a contribution on the subject, so excellent, and written by such a master in the art of observation, that I think it best to reproduce it for the benefit of my readers. The writer signs himself "A Bush Naturalist." In connexion with the overwhelming swarms of these curious animals,—"Now that attention generally is rivetted upon this extraordinary increase of a wild animal under the shadow of civilization, a paper on 'What is a marsupial?' may perhaps be interesting to many of those who are engaged in slaughtering them by thousands.

"The term Marsupiata, or Marsupialia, is derived from the word marsupium—a purse or bag—and has reference to the well-known pouch for carrying the young with which we are all so familiar in the kangaroos and opossums; but it is not so well known that many of our marsupial animals have hardly any pouch, and some even none at all. In the peramelidai genus (bandicoots, &c.) the open end of the pouch is, strange to say, downwards, the bag itself extending upwards, or exactly contrary to the way it is in the kangaroo, opossum, kaola, and wombat. In the dasyuridce genus (native cats, phascogale, &c.) there is no pouch at all. These carnivorous members of the family give birth to as many as five or six young at a time, and these, when born, are as immature as those of the kangaroo, and cling on to the teats of the mother in a similar way—-just as firmly, too, notwithstanding the lack-of a pouch to protect them. It has always been a wonder to me, when I have killed a native cat, and seen half-a-dozen of these delicate little lumps of flesh hanging to the teats by their mouth alone, how it is that they are not killed, or at least injured, by contact with the rough ground or the branches of trees as the mother runs about and hunts for food. One thing I have noticed—that they do not carry them so long, in proportion, as the kangaroos do their young, but make a nest instead. In the echidna (porcupine) the pouch is represented only by a curved wrinkle of the skin; and in the platypus it is quite absent, as also are the nipples, the milk exuding through exceedingly minute pores of the mammary gland; and yet these very different genera are all marsupials, the two latter belonging to the second section of the order—the monotremata.

"There are several peculiarities which join together this large group of animals—a group of which Australians may well be proud, for it contains among it members whose habits are as diversified as are their forms, for some are arboreal, some terrestrial, some aquatic, some most rapid burrowers, and others are actually aerial travellers. There are among them herbivorous species, as also are there cruel carnivora, insect-destroyers, and crab-catchers. They are a group which comprises many varieties of form quite unknown beyond our own sunny land—mysteries of anatomy, marvels of Nature's workmanship, which, when first shown to the old-world scientists, provoked a smile of incredulity as to their being real. The principal characteristic uniting all these species together is the fact that they are non-placental. The young of all other mammals are nourished until they attain to a large size, before being born, by having this placental connexion with the circulation of the blood of the mother, which enables the food partaken of by the mother also to nourish .the young. In the marsupiata this placental connexion is absent, but the life-germ may be detected in the uterus in a still more immature state than is seen by the kangaroo-hunters on the nipple. There being no placenta, it is unattached, and grows by absorption, of its own accord, seed-like, egglike, till born. In this respect, as well as in several others, the marsupials approach somewhat closely to the ovoviviparous creatures.

"Bushman as I am, and having killed and roughly examined some hundreds of kangaroos, &c., I of course was strongly inclined to the opiniou expressed by your correspondent, Mr. M'Arthur (February 8) that the young grew out of the end of the nipple; but when I came to read how much the subject had been studied by anatomists, I found the teat theory would not hold. It is a fact that the young can be found in the first uterus, as stated above, and also that there is no possible connexion with the external uterus, or pouch.

The only point not proved is the actual passage from the one to the other. But, supposing that the young foetus did descend the teat, or that the teat was drawn up, inverted glove-like for that purpose, it does not overcome the difficulty of how this immature little lump of flesh manages to fix itself on the outside of the teat, unless it has the power also to (glove-like) turn itself inside out; and if the creature descends the birth-teat (as some suppose), and fixes itself on to a milk-teat, the same difficulty still occurs—i.e., how does it do it ? Australians must remember that marsupials have been known ever since the discovery of America, and that for the last hundred years—that is, since Captain Cook's time, when the kangaroo was discovered—no animals have been more studied and examined by the anatomist and zoologist; and a bushman's crude opinion and rough external examination has no weight in opposition to the anatomical dissections of such men as John Hunter, Sir E. Horne, Geoffrey Saint Hilaire, Cuvier, De Blainville, Owen, and others. We bushmen are on the wrong track when we look into the pouch of the kangaroo in order to elucidate the mystery of the birth of their young; we must turn back and try a fresh cast—attain some considerable anatomical knowledge, and learn to dissect —then we shall find that we are travelling over old ground; that others have long since found out the way which to us is unknown. When such an authority as Professor Owen, of London—the greatest of living comparative anatomists, the most learned paleontologist of the day—pledges his word that the young kangaroo is born on its thirty-ninth day of gestation, and this from his actual daily examination of a tame doe in the Zoological Gardens in London, and also after the anatomical dissection of the numbers that have passed through his hands, we may safely accept his conclusions. The actual transit of the little one into the pouch was not seen by Mr. Owen, although he examined the teat daily; it was not till the Thirty-ninth day that it appeared, and it was then firmly attached to the nipple, and of a length not exceeding 1 in. and 2 inches. The species was the common great kangaroo (Macrojpus major). Four days after birth, he detached the young one in order to see if it had the power of regaining the nipple, but after two days he examined the pouch and found it empty. Every portion of the litter was carefully searched, in the hopes of finding the foetus, but without success; the mother, therefore, it was supposed, had destroyed it in consequence of the disturbance.

"In the Zoological Journal, vol. v., p. 239, an instance is given of a young foetus which was only a degree larger than the one detached by Professor Owen, for it was ' only the size of the last and half the middle joint of one's little finger; its integuments of a flesh-colour, and so transparent as to permit the higher-coloured vessels and viscera to shine through them.' This minute specimen, although it made no effort to regain the teat when held close to it, yet in two hours' time after it had been experimentally detached had regained it and was as well as before. In the ' Transactions of the Linneean Society,' vol. xvi., is mention of a similar experiment on a foetus the size of a rat; and this also, after two hours' separation, had regained its hold, and was none the worse.

To the mode of birth of the young marsupial (except of the monotremata), the only query being as to how this feeble lump of delicate flesh manages to attach itself so firmly by the mouth to the nipple of the dam. I would ask your correspondent, Mr. McArthur, whether, in the case of the carnivorous marsupials (dasyuridce) which I have, as before stated, found with six young, each hanging to its own nipple, if he supposes all these nipples are inverted at the time of conception, and that each receives its individual germ? Without being an anatomist, it is evident to any one that in the case of the anterior nipples this could not possibly be the case. It is supposed that the mother takes up the little one in her lips and places it in the pouch.

"Microzoon,' the scientific contributor to the Australasian, in 1869 (I think) stated that4 several of both the American and the Australian marsupials have been watched-at the time of parturition, and there can be no doubt of the young being brought forth in the ordinary way of other mammals, taken up by the lips of the mother, and fixed in this way upon the teat; in the case of the kangaroos, the female has been seen often holding open the aperture of the pouch, and, plunging the head to the bottom of it, replacing the young which had been experimentally detached.5 My own impression is that the nipple is capable of a certain degree of erectile rigidity (no uncommon thing in mammce), and so the animal is enabled to pierce the tender mouth of the foetus as held to it by the lips of the mother. Against this theory of removal by the lips we must place the peculiarities of the echidna (porcupine). On this subject Mr. Krefft, late curator of the Sydney Museum, says, The manner in which the young {echidna) is brought forth and deposited in one of the two small cavities or pouches on the abdomen, which are destitute of nipple's, is a wonder to me. In the case of the kangaroo, or even of the clumsy wombat, the lips may convey the new-born young to the teat; but here is an animal without lips, and with the stiffest of great unwieldy claws, and yet it has the means of housing its young, which are about the size of a large tick, securely in its abdominal receptacle, where nothing secures it but its own great claws; even in so young a creature, these are already powerfully developed. As there are no nipples in the echidna, what becomes of the inverted-nipple theory in-their case? Botanist, in the Queenslander, says that his black boys say that the echidna lays white eggs, and the platypus black ones. Perhaps they do, and the young, when they emerge from the egg, if the mother is at that time lying on the egg, are thus enabled at once to cling to the abdomen. I believe it is still an open question as to whether these mono-tremes are oviparous, or bring forth the living young. What are our lynx-eyed Australian youth about that, although the country has been settled for a hundred years, they have not found out all about the young of the echidna and platypus?

The next peculiarity, which is a most constant characteristic of a marsupial, is the presence of the marsupial bones. These are two bony pieces extending one on each.side, upwards and outwards from the pubis, where they converge, and to which they are joined. These bones are common to both sexes, and only absent, I believe, in one species—the thylacinus, or tiger-wolf, of Tasmania. Professor Owen says that  both sexes of the marsupial genera in various ways3 manifest their affinity to the oviparous classes, and also that 4 the marsupial bones so common in the skeletons of reptiles are limited in the mammiferous class to this division, in which alone, from the peculiarly brief period of uterine gestation and the consequent non-enlargement of the abdomen, their presence might be expected. But these bones serve important purposes in relation to the generative economy of the marsupiata. In the female they assist in producing a compression of the mammary gland necessary for the alimentation of a peculiarly feeble offspring, and they defend the abdominal viscera from the pressure of the young as these increase in size during their mammary or marsupial existence, and still more so when they happen to return to the pouch for shelter. The author (Professor Owen) next proceeds to point out the uses of these bones in the males, which have peculiarities corresponding to the pouch in the female— ad characters supra dictos addantur in maribus situs testium ante penem, et in feminis vagina in duas canales septo di-visa.'3 These bones are also to be found in tho subdivision monotremata. The young marsupial has not, when very young, the power to suck; the milk is ejected by the mother.

"Another distinguishing characteristic of a marsupial is one on which scientific anatomists lay great stress, but which to me, I confess, seems unimportant, for no use can be found for it; it is the celebrated 4 inflected angle of the lower jaw.' I will quote from Krefft to explain this technical phrase: Let me explain my words to those who may have the jaw of an opossum or wallaby at hand. The flat process rising up just from behind the last tooth is called the "ascending ramus." This bone dips down again and then expands to the right and left, producing the "condyle," which works against the skull and causes the jaws to move. At the inside base of this condyle the jaw or mandible enlarges, spoonlike, forming in kangaroos, phalangers (opossums), and wombats a deep hollow, and in the carnivorous tribes a hooked process, well turned in. In the Icaola (native bear) this piece of bone is reduced to a notch, which is very slightly bent inwards at the tip only.' As the monotremata (echidna and platypus) are the only exception to this law, the characteristic is a good and very strange distinguishing point as applied to our existing marsupials; but I remember reading somewhere that in some of our gigantic fossil marsupials it is not to be observed. So exclusively is this trifling variation a feature of ' what constitutes a marsupial' that in only one other mammal in the whole world— the Madagascar centetee—is it to be found.6 Another remarkable peculiarity of a marsupial is the permanent separation of the bones of the skull; they do not anchylose in the adult and old individual, as do most of the bones of the skull in placental animals7 By this peculiarity our Australian animals show their alliance with the reptilia, among whom this separation is the common rule.

"In undertaking to write as to what constitutes a marsupial it is necessary that I should refer to yet another peculiarity, which,. I must own, is a little beyond my own or the ordinary bushman's technical knowledge, but which, for the sake of the more anatomically learned among the Queenslander's many readers, I must not leave out, or my paper would be incomplete. I will quote from ' "Waterhouse's Marsupials :' 'Agreeably to this view connected with the ovovi-viparous generation of the marsupiata, and with an inferiority of intelligence which Professor Owen observed in these animals in confinement, he was induced to undertake a careful examination of the brain in the various marsupials, and the result was a most interesting discovery. Besides the decreased size of the hemispheres of the brain, and consequent exposure of the cerebellum, indicative of alow grade of organization, the corpus callosum and septum lucidum were found to be "entirely wanting in these animals, or at least existing in only a rudimentary state. Now the corpus .callosum, which is the principal bond of union between the opposite hemispheres of the brain, had been regarded as the great characteristic of the brain in the mammalia, and in fact this commissural apparatus presents the essential difference which exists between that and the oviparous vertebrate classes.'

"The reader who takes interest enough in this subject to have followed me will now begin to see 4 what constitutes a marsupial,' and to find, notwithstanding the name, that the pouch has very little to do with it. First, there is the chief peculiarity—their being non-placental; then there are those curious marsupial bones; then there is the apparently useless, but nevertheless invariably found, inflected angle of the lower jawbone; then there is the divided state of the bones of the skull; then the small brain and the want of the corpus callosum and the septum lucidum. The observant reader will also see that in many respects the order approach nearly to an allianee with the reptiles, and to the egg-laying vertebrata—an alliance which, in the division monotremata, is still more clearly to be traced. Many naturalists have wished to break up the order, distributing them among the other mammals according to their teeth, toes, opposable thumbs, &c.; but the clever anatomical investigations of Professor Owen discovered in how many curious ways the whole group agreed— carnivorous as well as herbivorous, aerial as well as aquatic, American and Australian representatives; and they are now admitted to be a distinct grand division of Nature, as are the mammalia, the birds, or the reptiles."


Return to Book Index Page


 


This comment system requires you to be logged in through either a Disqus account or an account you already have with Google, Twitter, Facebook or Yahoo. In the event you don't have an account with any of these companies then you can create an account with Disqus. All comments are moderated so they won't display until the moderator has approved your comment.

comments powered by Disqus

Quantcast