« PreviousContinue »
extent or variety of its tunnels, or that the animal works upon a regular system, and does not burrow here and there at random. How it manages to form its burrows in such admirably straight lines is not an easy problem, because it is always in black darkness, and we know of nothing which can act as a guide to the animal.'
The ordinary molehills with which everyone is so familiar are nothing more than the materials which the creature throws out from its burrow; and, if they be carefully opened after the rain has consolidated the heap of loose material, nothing more will be discovered than a simple hole leading into the tunnel. But let us strike into one of the larger tunnels, as any molecatcher will teach us, and follow it up until we come to the real abode of the animal.'
The mole's encampment or fortress, in which it resides from the autumn to the spring, is a very complex structure ; it must be stated that this domicile is totally distinct from the nest in which it brings forth its young, and is separated often at some distance from it. The fortress is formed under a large hillock of considerable size, but ‘not very conspicuous, because it is always placed under the shelter of a tree, a shrub, or a suitable bank, and would not be discovered but by a practised eye. The subterraneous abode within the hillock is so remarkable that it involuntarily reminds the observer of the well-known maze with which the earliest years of youth have been puzzled throughout many successive generations. It is not easy to give a recog. nisable description of the mole’s encampment without an illustration; there is a central apartment, or keep, forming a nearly spherical chamber, situated at the bottom of the mound; this is the only room which the structure contains, all other portions of the domicile consisting of passages of peculiar form. Around this chamber are driven two circular galleries, one just level with the ceiling, and the other at some height above. These two galleries are of unequal diameter, the upper one nearer to the apex of the mound being the smaller; they are connected together by five nearly equidistant passages, but the only entrance into the keep is from the upper gallery, out of which three passages lead into the ceiling of the keep; so that the mole, before he can gain admittance into his parlour downstairs, when once he is in the lower gallery, has to ascend to the garrets, from which he must again descend one of the three passages which, as already said, lead to the keep. Besides the passages we have mentioned there are eight or nine others, the orifices of which, with a view to make the roads as complicated as possible
, are never formed opposite to those which connect the lower with
the upper gallery. We have said that the mole cannot get into his parlour from the lower gallery without climbing into the upper one. We must not forget, however, to mention that there is a passage which is situated at the bottom of his parlour leading to the main road :
* This high road,' to quote the words of Professor Bell, differs essentially from all the other routes and excavations, both in its construction and use. It extends from the fortress to the extremity of the domain in nearly a direct line, forming, in fact, the main route of communication between the fortress and the different parts of the encampment; and the alleys which lead to the hunting-ground, or quarries, open into it on each side. Its circumference is larger than the body of the mole, though not large enough to admit of two individuals passing each other. The walls are beaten by the frequent pressure of the animals' sides against them until they become very smooth and compact. . . . . In some instances the same mole forms a second and a third road; but this is generally done in order to extend its operations to a new and a more productive district. In other cases many moles are known to employ one road, though they never intrude upon each other's hunting-ground. In this case, should two of them meet, one must retreat into the nearest alley, or a battle ensues, which proves fatal to the weaker of the combatants.'
It is in these high roads that the mole-catchers set their traps ; for the animals are constantly traversing them, as by these means alone they are able to visit their different hunting-grounds. Mr. Wood considers the use of so complicated a series of cells and passages to be extremely doubtful. The only object, he says, that can at present be surmised is that the rightful owner may rest safely in his middle chamber, and that in case of alarm, he might escape through either of the many passages which surround his home. But surely this only object' is an obvious and satisfactory explanation, as the excellent living naturalist, whose words we have quoted above, observes: - Nothing can be imagined more admirably calculated to ensure the security or the retreat of the inhabitant than such an arrangement of internal routes of communication as this. The chamber communicating beneath directly with the road, and above with the upper gallery, —this with the lower of five passages, and the latter again with the road, by no less than nine,-exhibit altogether a complication of architecture which may rival the more celebrated erections of the beaver.' We want information with regard to whether it is the male alone that constructs the fortress, or whether he is aided in his excavations by his faithful partner. Is not the latter allowed admittance, and a winter abode in the same apartment, or where does she spend the inclement season?
The nest of the mole is never placed in one of the keeps; it is formed by excavating and enlarging the point of intersection of several passages, and is made of grass, leaves, &c.; the young are produced in the spring.
Doomed to hard labour more than any other member of the mammalian mining classes, the mole has accordingly been provided with every requisite for this purpose. Its cylindricalshaped body, its soft and silky fur, each hair of which being inserted in the skin at right angles to the surface enables it to move backwards and forwards with ease, the amazing strength and the structure of its fore arms and hands, the latter combining, in mechanical efficiency, the united office of the spade and pitchfork, the elongated cranium, the peculiar bone for the support of the pointed muzzle,-a living auger,-the extraordinary muscular development of the neck, strengthened by another peculiar bone in the cervical ligament, the outward direction of the palms of the wide hands,—all these are points in the organisation of the mole which render it admirably fitted for the work it has to perform.
‘Had this creature,' Mr. Wood well observes,“ been a rare and costly inhabitant of the tropics, how deep would have been the interest which it would have excited. How the scientific world would have crowded to see the marvellous structure of a skeleton wherein are several accessory bones, and which exhibit peculiarities hitherto found only in fossil remains! How great would have been the admiration evoked by its soft, velvet-like fur; its tiny eyes deeply hidden in the fur, so as to be sheltered from the earth through which the animal is continually making its way; the strange mixture of strength and softness in the palms of its fore feet, and the elastic springiness of its nose. But because it is a native of our own country, and to be found in every field, there are but few who care to examine a creature so common, or who experience any feelings save those of contempt or disgust, when they see a mole making its way over the ground in search of a soft spot in which to burrow, or pass by the place where the mole-catcher has strung up his victims on the trees, as Louis XI. was accustomed to suspend the bodies of those who had committed the crime of trespassing on the royal domains.'
Closely allied in outward form and habits to the mole are the shrews, so common in every field and lane; they are burrowing animals, but not such efficient miners as the first-named creature. So extremely flexible are the noses of some of these little soricide that they sometimes serve the purpose of the elephant's proboscis! Mr. Peale mentions that a shrew mole in his possession was able to bend the snout to such an extent as to force food into its mouth! Weasels and otters are believed by many people to be burrowing
animals, but there is much reason to think that this is not the case, and that these tenants of subterranean abodes have taken advantage of some ready-made cavity.
Opposite page 22 in Mr. Wood's work is a spirited drawing of a prairie dog 'town,' the name given by hunters to the localities frequented by the very interesting little animal, the wishtonwish (Spermophilus Ludovicianus), of the banks of the Missouri and its tributaries. In spite of the name the animal is no dog, but a rodent, related to the European marmot. prairie dog villages vary considerably in extent; some occupy an area of a few miles only, others cover a large tract of country ; they consist of numerous small mounds varying in size, some reaching a height of sixteen inches, others barely rising above the surface of the ground. The form is that of a truncated cone, the base being about two or three feet in circumference.
According to Mr. Say, the entrance to the burrow is either at the summit or at the side of the mound; the hole at first descends vertically to the depth of one or two feet, whence it continues downward in an oblique direction. Many individuals occupy one burrow, and may be seen sporting about the mounds; now diving into the holes, but quickly popping their heads out again. Not unfrequently very undesirable acquaintances enter the home of the little wishtonwish, in the shape of rattlesnakes and owls, who resort thither both for the sake of comfortable shelter, and of making a meal on the junior members of the prairie dog's family. But 'in spite of the formidable foes by which it is attacked, and which take up their residence in the very centre of its habitations, the prairie dog is an exceedingly prolific animal, inultiplying rapidly, and extending its excavations to vast distances. Indeed, when once the prairie dogs settle themselves in a convenient spot, their increase seems to have no bounds, and the little heaps of earth which stand near the mouth of their burrows extend nearly as far as the eye can reach.' During the winter these animals keep within their homes in a semi-dormant condition; the entrances to the burrows are closed up, and each individual forms a compact ball of dry grass with a small aperture at the top, in the centre of which he sleeps warmly and securely.
We must not linger too long over the many interesting instances of burrowing mammalia ; but there is one strange looking creature of the mouse tribe which excites so much curiosity by the questionable shape of its head, that we must not pass it over without a brief notice; we allude to the gopher or pouched rat of Canada (Pseudostoma bursarius). In the general form of its body it partly resembles a rat, and partly
a mole; but its chief peculiarity lies in the possession of a pair of large oval-shaped pockets or pouches, one on each side of the creature's cheek, which, when distended with food, present a most extraordinary appearance. These pockets open internally into the mouth, one on either side of the cheek ; they seem to serve the purposes of a portable larder, the food being stuffed into these natural sandwich-boxes and consumed at the pleasure of the animal. At one time it was supposed that these pouches were used for the purpose of conveying away from the burrow the excavated soil, as they were frequently found filled with earth ; but this was done by the natives who had killed specimens, for the sake of preventing the collapse of the pockets.
Like the mole, the gopher throws up little hillocks at regular intervals, sometimes twenty or thirty feet apart, and sometimes crowded closely together. The nest of the gopher is made in a burrow constructed expressly for the purpose, and is placed in a small globular chamber about eight inches in diameter. The bed on which the mother and her young repose is made of dried herbage and fur plucked from the body. This chamber is the point from which a great number of passages radiate, and from these other tunnels are driven. These radiating burrows evidently serve two purposes, enabling the animal to escape in any direction when alarmed, and serving to conduct it to its feedinggrounds.' These creatures are said to do much mischief in gardens to which they frequently gain admission, by eating off the roots of the plants which grow there. As it is almost a foot in length, and has very large sharp projecting incisor teeth, the gopher is eminently fitted to cause great devastation in cultivated grounds. The strange-looking edentate animal of South America, called the Pichiago (Chlamyphorus truncatus), is admirably adapted for scooping its long galleries in the soil; this creature is furnished along the whole length of a large portion of its body with a curious cuirass or coat of mail, which protects the head and back, and when it reaches the tail it turns abruptly downwards, as if on hinges, and forms a kind of flap over the hind quarters, which are short and square;' hence the specific name of truncatus.
The pichiago is rather a rare animal, being confined to the districts about Mendoza, on the east of the Cordilleras. The coat of mail is as flexible as the chain or scale armour of the olden times, and accommodates itself to every movement of the animal.' An examination of the skeleton of the pichiago will convince any one of the animal's efficiency as a miner; its pointed muzzle and strong bones of the head, its short arms, vided with broad palm-shaped feet, furnished with five long,