Encyclopædia Britannica, Ninth Edition/Spitzbergen
SPITZBERGEN. This group of rocky, barren, and snowclad islands, lost in the solitudes of the Arctic Ocean, 400 miles north-north-west of the North Cape of Norway (see vol. xix. pl. II.), but nevertheless well known for at least four centuries to European whalers and seal-hunters, has of late acquired new interest from the scientific expeditions by which it has been selected either as a base for attempts to reach the north pole or as a field in which to inaugurate a new era of scientific exploration in the arctic regions. From Spitzbergen Parry started in 1827 on the sledge journey which brought him within 480 miles of the pole; it was the starting-point of the investigations which led Charles Martins to his brilliant generalizations of the flora, present and past, of the earth; and numerous Swedish expeditions from 1858 onwards have accumulated an amount of knowledge, so vast and so important, as to be comparable only with the results of the great equatorial and arctic journeys of the first years of the 19th century.
The Spitzbergen archipelago, lying between 76° 30' and 80° 30' N. lat. and 10° and 30° E. long. — half-way between Greenland and Nova Zembla — consists of six large and a great number of smaller islands. The chief, that of West Spitzbergen, shaped like a wedge pointed towards the south, and deeply indented on the west and north by long branching fjords, has an area of nearly 15,200 square miles. High mountains, reaching 4560 feet in the Horn Sound Tind, cover its southern parts; while a wide plateau, with an altitude of from 1500 to 2000 feet and covered by a thick ice-sheet, occupies the north. Several fjords — Horn Sound, Bel Sound, Ice Fjord (15 miles wide and 80 long), and the double fjord of King's Bay and Cross Bay on the west, and Liefde, Wiide, and Lomme Bays on the north — deeply penetrate the island. One of the ramifications (Dickson Bay) of the beautiful Ice Fjord, 150 fathoms deep, nearly reaches the head of Wiide Bay, so as almost to divide the island. A long narrow island, Prince Charles's Foreland, with peaks of nearly 5000 feet high, runs parallel to part of the west coast of West Spitzbergen, from which it is separated by a narrow strait. The broad Stor (Great) Fjord, or Wiide Jans Water, separates the main island from two others to the east, — Stans Foreland (2500 square miles) and Barents Land (580 square miles). Formerly these were considered as one, and named Edge Island, until the narrow Walter Thymen Strait which parts them was discovered. A few peaks, estimated at from 1600 to 2000 feet high, protrude above the snow and ice by which these two imperfectly explored islands are covered. To the north-east of West Spitzbergen, separated from it by Hinlopen Strait (7 to 60 miles in breadth) lies North-East Land, with an area of about 6200 square miles. Its western and northern coasts are indented by several bays and fjords; the southern and eastern shores, on account of the masses of ice by which they are constantly girt, remain unexplored. This island appears like a broad plateau covered by an ice-sheet 2000 to 3000 feet in thickness, from which a few peaks protrude. Slowly moving towards the east, this immense sheet of ice discharges into the sea by a huge ice-wall, unbroken by promontories for 150 miles, thus forming the broadest glacier known, — Dickson's glacier. Eastwards from this group of islands, 100 miles to the north-east of Stans Foreland, rises another island, measuring 90 miles from west to east. Marked either Gillis's Land or Wiche's Land in earlier maps, it was seen from Spitzbergen as a snow-clad mass mingling with the fogs of the sea by a Swedish expedition, and later on by Heuglin and Zeil; but it was not until 1872 that the Norwegian whalers Altman, Johnsen, and Nilsen reached it from the east and nearly circumnavigated it. After some discussion about its name, it has received from Professor Mohn the name of King Charles Land, which is now generally accepted. The wide strait which separates it from Spitzbergen is called Olga Strait. It is now established that Gillis saw Gillis's Land to the north-east of the archipelago, and this land, which may perhaps be a link between the Spitzbergen archipelago and that of Franz-Josef, has been again sighted by Norwegian seal-hunters. Numerous small islands lie around the larger: — the Danes and Norwegians Islands on the north-west, the Seven Islands on the north, Outger Reps, Brock, and Charles XII. Island on the north-east, Waygat Islands and William I. Island in Hinlopen Strait, the Ryk Yse Archipelago, Hope Island, and the Thousand Islands (about a hundred small rocks) to the east and south of Stans Foreland, and many other smaller ones. Many of these small islands rise to a height of 1500 to 1700 feet.
The archipelago, which has the Greenland Sea to the west and Barents Sea to the east, rises from a submarine platform that extends from Bear Island north-eastwards to Franz Joseph Land, and probably was an immense arctic continent connected with Greenland during the middle of the Tertiary period. The sea around Spitzbergen has a depth of less than 100 fathoms. Owing to this circumstance the ice readily accumulates round the shores; and, although the glaciers of Spitzbergen do not give origin to icebergs so huge as those of Greenland, the smaller icebergs and the pack-ice are thick enough to prevent access to the shores except for a few months in the year. Happily the Gulf Stream, which washes the shores of Norway, after sending a branch to the east, flows north to the western shores of Spitzbergen, moderating its climate, and leaving an open passage which permits whalers to approach the western coast even under the most unfavourable conditions of ice in the arctic regions. Drift-wood brought from lower latitudes, glass-floats of the Norwegian fishermen, and even the large seeds of the Entada Gigalobium, carried by the Gulf Stream from the Gulf of Mexico, are found at the northern extremity of Spitzbergen. On the other hand, a cold current charged with ice descends from higher latitudes along the eastern coast, rendering approach extremely difficult. On this account King Charles Land remained unknown until 1872, and the eastern coast of North-East Land still continues unexplored.
Owing to the warm current, the climate of Spitzbergen is less severe than in the corresponding latitudes of Greenland and Smith Sound. The isotherm of 23° Fahr. (-5° C.), which crosses the middle of Eastern Siberia, touches its southern extremity, and only the north-east coasts of West Spitzbergen and North-East Land have an average yearly temperature so low as 14° to 10°.5 (-10° to -ll°.9 C.). At Mussel Bay (79° 53') the average yearly temperature is 16° (January 14°.1, July 39°.3). Bear Island, notwithstanding its more southerly position, has a lower temperature, as the Gulf Stream does not touch it. Even in the coldest months of the winter a thaw may set in for a few days; but, on the other hand, snow sometimes falls in July and August. Spring comes in June; the snow becomes saturated with water and disappears in places, and scurvy grass and the polar willow open their buds. By the end of June the thermometer has ceased to sink below the freezing-point at night; July, August, and September are the best months. In September, however, autumn sets in on shore, though the whalers continue cruising until the end of the month and even reach the highest latitudes. By the end of September the pack-ice rapidly freezes into one solid mass. To move on this mass, however, is exceedingly difficult, for the ice, owing to its contraction and expansion, is either intersected by large fissures or broken up and piled into heaps, which puts insuperable difficulties in the way of sledge expeditions.
Glaciers are largely developed. On the high grounds the snow under a level of from 1200 to 1500 feet disappears every year; but on the plateaus it continually accumulates, so as to cover them with an immense ice-sheet, like that of Greenland, which slowly discharges by the valleys towards the sea in the form of immense glaciers. All North-East Land and the interior of West Spitzbergen are covered with such ice-sheets, which descend to King's Bay by a glacier 15 miles wide, or by that already alluded to in North-East Land, where the ice-cliffs are from 200 to 400 feet high. These glaciers, however, discharging into comparatively shallow waters, do not produce such icebergs as those of Greenland. The glaciers of the present epoch are but trifling in comparison with what they were during the Glacial period, when the entire country was buried under an ice-sheet, which probably connected all the archipelago into one ice-bound continent and spread far beyond to northern Europe.
The backbone of the islands consists of thick layers of granite, gneiss, and other archaic schists. But more recent formations bearing witness to a much more genial climate are not wanting. The Carboniferous period is represented by extensive coal-bearing strata, the lowest of which are intermediate with the Devonian (Liefde Bay strata). The Trias, also containing a rich fossil flora, is represented by black clay slate. The Jurassic deposits are widely spread; they mostly belong to the Kelloway, and many of them are coal-bearing. To the same period belong the frequently occurring layers of what was formerly called hypersthenite, but has now been proved to be (according to Zirkel's classification) diabase and dolerite. The most interesting formation is, however, the Miocene. At a period close, geologically speaking, to the subsequent Glacial period, and even to our own, Spitzbergen was covered with a luxuriant vegetation the like of which is now found only in the 60th parallel in Scandinavia. The shores of Bel Sound, Ice Fjord, and Cape Starostine in 78° N. lat. were covered with extensive peat bogs, on the edges of which the marsh cypress flowered, dropping its leaves and blossoms into the marshes. Sequoiæ, poplars, birches, planes, and large oaks also grew there, while ivy and thick underwood freely developed under their shadow, and thousands of insects swarmed in the thicket. The most striking feature of this Miocene vegetation — a feature conclusively established by the researches of Oswald Heer — is that Spitzbergen, Greenland, Franz-Josef Land, and Nova Zembla were at that time parts of one immense continent, thus realizing the very conditions for the coldest climate, if climate had to depend on telluric causes only. Heer has shown, moreover, in a manner that hardly admits of doubt that the luxuriant vegetation so unmistakably borne witness to by the Miocene strata of the arctic regions could not have developed had it been condemned to endure the long arctic night it now undergoes. This feature of the arctic Miocene flora is unexplained, and will remain so until higher cosmical laws are formulated to explain changes of climate. A change in the position of the earth's axis of rotation (recently the subject of a serious discussion in England and on the Continent) would seem to be the only adequate hypothesis by which to account for the warm vegetation of the period in question in such proximity to the pole; but this hypothesis would be so much at variance with the present state of our knowledge that we may well hesitate to advance it. A brief recurrence of a warmer climate not nearly so warm as the Miocene, yet somewhat warmer than the present was also experienced by Spitzbergen after the long period of glaciation as is proved by the occurrence of beds with mussels, which are now found only in much warmer latitudes. This warmer Post-Glacial period — traces of which have been met with throughout the arctic and subarctic regions — was followed by a period of slow upheaval, which still continues.
The flora is of course poor. The only tree is the polar willow, which does not exceed 2 inches in height and bears a few leaves not larger than a man's finger-nail; and the only bush is the crowberry (Empetrum nigrum), to which the recently discovered cloudberry (Rubus Chamæmorus) may be added. But at the foot of the warmer cliffs some loam has been formed notwithstanding the slowness of putrefaction, and there, in contrast with the brownish lichens that cover the hills, grows a carpet of mosses of the brightest green, variegated with the golden-yellow flowers of the ranunculus (R. sulphureus and hyperboreus), the Sileneæ, the reddish heads of the Pedicularis, the Oxyria reniformis (a foot high), the large-leaved scurvy grass (Cochlcaria fenestrata), several saxifrages, Cerastium alpinum, Potentilla emarginata, fox-tail grass (Alopecurus alpinus), Dupontia Fischeri, Poa cenisia, pratensis, and stricta, with a few large-flowered Polygona and Andromedæ; while on the driest spots yellow poppies and whitlow grasses (Drabæ), Cardamine bellidifolia, several Dryadeæ, &c., are found. Even on the higher slopes, 1500 feet above the sea, the poppy, Luzula hyperborea, and Stellaria Edwardsii are occasionally met with. Mosses, mostly European acquaintances, cover all places where peat has accumulated. The slopes of the crags and the blocks of stone on the beach are sometimes entirely covered with a luxuriant moss and lichen vegetation, among the last being the so-called “famine bread” (Umbilicaria arctica), which has maintained the life of so many arctic travellers. Flowering plants are represented by as many as ninety-six species, of which eighty-one grow in Greenland and sixty-nine in Scandinavia; forty-three species are alpine cosmopolites, and have been met with on the Himalayas. The ferns are represented by two species. Although thus limited in number, the flora is suggestive in its distribution. The vegetation of the south has a decidedly Lappish or European alpine character, while that of the north coast is decidedly American, and recalls that of Melville Island. Many flowering plants which are common in north-west Spitzbergen are absent from the east coast, where the cold current is inimical to both flora and fauna; but, on the other hand, one moss (Pottia hyperborea) and one lichen (Usnea melaxantha) are found there which are of American origin and grow both in North America and on the Cordilleras. Algæ, are most numerous, many, like the brown Laminaria and Nostoc communis, which fill all pools and are the chief food of many birds, being familiar in Europe. Protococcus nivalis covers the snow with its reddish powder.
The fauna, although not very rich in species, is exceedingly rich in individuals. It includes fifteen mammals, only two of which are terrestrial — the reindeer and the ice-fox — besides the usual inhabitant of the arctic regions, the polar bear. The number of reindeer is really puzzling. In a single summer, or rather in the course of a few weeks, no fewer than from 1500 to 2000 reindeer were killed by hunters for several consecutive years previous to 1868. Much emaciated in June, they grow very fat towards the end of the autumn, after feeding on the mosses. Great numbers are “marked” (that is, have both ears cut at the same height), and the hunters are persuaded that these individuals come from an unknown continent in the north-east, where they have been marked by the hand of man. However strange this hypothesis, it must be acknowledged that the objections urged against it by the Swedish explorers are not conclusive, and that frost-bite attacking young calves could hardly account for the symmetrical markings on both ears. The immense numbers of the reindeer strongly support the idea of their migration, and the only question is whether they came from Siberia via Nova Zembla, or whether they did not really come from the unknown archipelagoes on the north-east, the existence of which is supported by so many other data (immobility of the ice to the east of Spitzbergen, dirty ice, birds met with off North-East Land, as well as several other considerations of a more general character).
Eight Cetaceans are met with in the seas off Spitzbergen, viz., — Balænoptera boops, 80 to 110 feet long; B. gigas and B. rostrata, 30 feet long; the white whale (Beluga catodon), three species of seals (Phoca barbata, grœnlandica, and hispida), and the walrus (Trichechus or Odobænus rosmarus). The Greenland whale has completely disappeared in consequence of the great havoc made during the last two centuries: according to Scoresby, no less than 57,590 individuals were killed between 1669 and 1775. A perfectly reckless extermination of seals is still going on. Numberless walruses tumble about in the water, or lie in crowds on the floating ice; and their number further increases when the flocks of Greenland seals arrive in August.
Birds visit the archipelago in such vast flocks that the cliffs are literally covered with them. The fulmar petrel (Procellaria glacialis) — a herald of polar regions — meets the ships approaching Spitzbergen far away from the coasts. Its colonies cover the cliffs, as also do those of the glaucous gull (Larus glaucus), or the “burgomaster.” Rotches (Mergulus alba), black guillemots (Uria grylla), ivory gulls (Larus eburneus), auks, and kittiwake gulls (Larus tridactylus) breed extensively on the cliffs, while geese, looms, and snipe swarm on and about the lagoons and small freshwater ponds. The bernacle goose (Anser bernicla) is only a bird of passage, as it goes farther north-east to nest. The eider breeds in large colonies on the islands, where its young are safe from the ice-fox, only the glaucous gull and the brent goose (Bernicla brenta) being admitted to keep them company, while the lumme (Mormon arcticus) and the tern confine themselves to separate cliffs. These birds, however, are only guests in Spitzbergen, the snow-bunting (Emberiza nivalis) being the only species which stays permanently; twenty-three species breed regularly on Spitzbergen, and four others (the falcon, snowy owl, swan, and skua) come occasionally.
There are twenty-three species of fishes, but no reptiles. Insects are few: Lepidoptera (one species), Neuroptera (one), Hymenoptera (four), and Diptera (twenty) have been met with by the Swedish expeditions. Arachnids, and especially Pantopods, on the other hand, are very common. Molluscs are also very numerous, embracing no less than 130 species. In June several Limacineæ are met with in such numbers on the coast and at the mouth of the glacier streams as to constitute the chief food of the gulls. At some places the mussels and univalves reach a comparatively colossal size and appear in incredible abundance. Of Crustaceans no fewer than 100 species have been recognized in the waters of the archipelago.
The marine fauna is exceedingly rich in the bluish warmer waters of the Gulf Stream, and the dredgings of the Swedish expeditions, which were prosecuted even under the ice, never failed to bring to the surface a rich variety of remarkable or new forms. From a depth of 8400 feet the “bull-dog” machine lifted mud of a temperature of 33° Fahr. (0.3° C.) charged with Radiolarians, Polythalamæ, Globigcrinæ, Biloculinæ, Dentalia, and Nonioninæ, together with some Annelids (Spiochætopterus and Cirratulus), two Crustaceans (Cuma rubicunda and Apseudes), one Mollusc, two Holothuriæ, one Gephyrea, and one Sponge. Even at a depth of 15,900 feet animal life was found in unexpected profusion, the mud consisting almost entirely of brown and white Foraminiferæ, among them one Crustacean (a species of Cuma). But marine life is much poorer on the east coast, resembling that of Greenland.
Man does not live on Spitzbergen, and the attempts of the Swedes to winter there have for the most part proved failures, except in the case of the “Sofia” expedition, which succeeded in wintering without great loss, though not without suffering from scurvy. None but the Russian “Pomory ” (inhabitants of the Murman coast) have succeeded in enduring the arctic winters. The patriarch of Spitzbergen, the Pomor Staraschin (Starostine), spent no less than thirty-two winters (fifteen being consecutive) on the islands, dying of old age in 1826. There was a time in the 17th and 18th centuries when thousands of Dutch, Danes, and others were attracted to Spitzbergen by the whale-fishing. Whole villages sprang up on the shores, the best being that of the Dutch — Smeerenberg — which is said to have been visited by 18,000 men in a single summer. The “right whale” having disappeared, the whalers ceased to visit Spitzbergen, and only quite recently an attempt has been made to renew the pursuit of the Balænoptera boops. The chief object of pursuit is the walrus, carried on by Norwegians; sea-birds and eider are also occasionally sought.
History. — Spitzbergen was discovered in 1596 by William Barents, and his companion, Cornelius Rijp, is believed to have circumnavigated the archipelago. Nevertheless it was long considered as a part of Greenland, and described under the names of East Greenland, Newland, King James's Land, until the old name of Spitzbergen gained the ascendency. But long before Barents discovered it the Russians had known it under the name of Grumant (a word of unknown origin), and when Chancellor arrived at Archangel in 1553 he learned that the Russians visited Grumant for hunting purposes. After the 17th and 18th century whalers, the Russians began to visit the group, chiefly for walruses, seals, foxes, reindeer, bears, and birds; their huts and crosses are met with at very many places on the coast. Many wintered for several consecutive winters. Since 1830 their visits have almost ceased. The Norwegians began to visit the archipelago about 1795, and their small vessels now visit the Spitzbergen waters in considerable numbers. In 1822 a party wintered successfully, but later attempts have for the most part proved fatal on account of scurvy. To these experienced arctic navigators — assisted by Norwegian savants — we are indebted for so many important discoveries in the Barents, Kara, and Siberian Seas.
Several expeditions have made Spitzbergen their base in attempts to reach the north pole. The Russian admiral Tchitchagoff visited it twice, in 1765 and 1766, and reached 80° 28' N. lat. John Phipps mapped the north of Spitzbergen in 1773, and reached 80° 37' N. lat. In 1818 Buchan and Franklin reached 80° 34' to the north of the archipelago. Clavering and Sabine in 1823 explored the islands, and Sabine made his remarkable magnetic observations, while Clavering reached 80° 20' N. lat. Parry, shortly after his return from his third voyage, went to Spitzbergen and reached 82° 44' N. lat. on sledges. In the same year the Norwegian geologist Keilhau visited the group and has related his experiences in a remarkable book, Resa i Ost og West Finmarken. The Swedish professor Loven was the first to undertake, in 1837, dredging and geological explorations in Spitzbergen and its vicinity. Next year a body of French, Swedish, Danish, and Norwegian naturalists, among whom was Charles Martins, visited the western coast. From 1858 onwards the archipelago has been the object of a series of scientific expeditions. At the suggestion of Lovén, Otto Torell, accompanied by Nordenskjöld and Quennerstedt, opened the series, making many important observations and bringing home rich geological collections. In 1861 a larger expedition led by Torell, Nordenskjöld, Malmgren, Chydenius, and Petersen set out with the object of finding how far it was possible to obtain a measurement of an arc of meridian of sufficient extent. This aim was only partly accomplished, but the expedition returned with an invaluable stock of various observations. The work of the measurement of the arc was completed in 1864 by another expedition conducted by Nordenskjöld, assisted by Malmgren and Dunér, who returned again with a vast number of new and important observations. This expedition was followed in 1868 by that of the “Sofia,” under Nordenskjöld, having on its scientific staff Holmgren, Malmgren, and F. Smitt, zoologists; Berggren and Fries, botanists; Lemström, physicist; and Nauckhoff, geologist. They were prevented by ice from getting higher than 81° 42' N. lat.; but, to use Oswald Heer's words, the expedition “achieved more and gave a wider extension to the horizon of our knowledge than if it had returned merely with the information that the ‘Sofia’ had hoisted her flag on the north pole.” In 1870 two young Swedish savants, Nauckhorst and Wilander, visited Spitzbergen in order to examine the phosphoric deposits, and two years later a colony was formed in Ice Fjord, and a small railway constructed to work the beds. The attempt, however, did not prove successful. Mr Leigh Smith and the Norwegian Captain Ulve visited and mapped parts of East Spitzbergen in 1871, returning with valuable information. They reached 81° 24' N. lat. In the same year Mr Lamont visited the archipelago. In 1872 a great polar expedition set out to winter on Spitzbergen with the intention of attempting in the spring to advance towards the pole on sledges drawn by reindeer. But the expedition encountered a series of misfortunes. The ships were beset in the ice very early in Mussel Bay, and, six Norwegian fishing vessels having been like-wise overtaken and shut in, the expedition had to feed the crews on its provisions and thus to reduce the rations of its own men. The reindeer all made their escape during a snow-storm; and, when the sledge party reached the Seven Islands, they found the ice so packed that all idea of going north had to be abandoned. Instead of this, Nordenskjöld explored North-East Land and crossed the vast ice-sheet which covers it. The expedition returned in 1873 with a fresh store of important scientific observations, especially in physics and submarine zoology. In 1873 Drasche, the geologist, paid a short visit to Spitzbergen, and the Dutch polar expedition approached it in 1882. In 1882 the Swedish geologists Naathorst and De Geer made a journey to which we are indebted for most interesting data about the flora of the islands. In the same year a polar meteorological station was established at Cape Hordsen for carrying on the observations desired by the international polar committee. The year 1883 being very favourable, the Norwegian walrus-hunters Andreasen and Johannesen pushed to the north-east of Spitzbergen and discovered new land to the north-east of the archipelago apparently extending as far as 39° E. long.
Bibliography. — The literature of the subject is very voluminous, and for full bibliographical details reference must be made to such works as Chydenius's Svenska Expeditionen til Spetsbergen, translated into German by Passarge (Jena, 1869); A. Leslie's Arctic Voyages of A. E. Nordenskjöld (London, 1879); and Chavanne's Bibliographie der Polar-Regionen, 1878. The earliest maps of Spitzbergen up to 1864 have been reprinted in a Dutch publication (Tijdschrift van het Aardrijkskundig Genotschap te Amsterdam, pt. iii.); it contains the maps of 1596, 1612, 1625, 1634, 1642, 1648, and so on. Petermann's Mittheilungen, with Ergänungshefte, the Geographische Jahrbücher, the Imer (journal of the Swedish Geographical Society), and the Journal of the Roy. Geog. Society contain more or less detailed accounts of all the Swedish expeditions up to date. The scientific results of the Swedish expeditions are embodied in very many papers, amounting to from 6000 to 7000 printed pages, reference to which will be found in the above-mentioned works and periodicals. Oswald Heer's Flora Fossilæ Arctica deserves special mention. Every volume of the memoirs and proceedings (Handlingar and Förhandlingar) of the Swedish Academy of Sciences contains some remarkable contributions to our scientific knowledge of the far north, and the same can be said of many volumes of the Christiania Academy of Sciences and the Swedish Geological, Botanical, and Zoological Societies. (P. A. K.)
- Bear Island, half-way between the North Cape and Spitzbergen, can hardly be reckoned to the Spitzbergen archipelago. It was formerly renowned for its hunting grounds, but is very seldom visited now. Lying outside the course of the Gulf Stream, it is almost entirely ice-bound.
- According to Mr Naathorst's researches in 1882 (Sv. Vetenskaps Akad. Handlingar, xx.; Botanisches Jahrbuch, iv.), the flora of Spitzbergen is composed as follows: — Rosaceæ, 7 species; Saxifrageæ, 10; Cruciferæ, 15; Ranunculaceæ, 8; Sileneæ and Alsineæ, 12; Salix, 2; Compositæ, 5; Scrophulariaceæ, 2; Ericaceæ, 2; Gramineæ, 23; Cyperaceæ, 12; Juncaceæ, 6; Filices (Ferns), 2; Lycopodiaceæ, 1. The whole of this flora immigrated during the Post-Glacial period, which was warmer than the present.
- The existence of the Arvicola hudsonia is not quite proved.