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Show 17R ISLAND LIFE. [rAnT T. . · 11 L d ·thin 8-l deO'rees of flowering plants. Even m Grmne an , Wl . of £ . . . . d t ty five speCies o oss1 1 the pole, a s1m1lar flora ex1ste , wen - . . . h plants avm. g b een co lle c t ed by the last Arctic exped1t10n, o. f which eighteen were ider;ttical with the speci~s from other Arctic localities. This flora comprised poplars, ~Irche.s, hazels, elms, 'b tlms and eiO'ht species of conifers, mcludmg the swamp v1 urn , o b · ) h' h d t cypress, and the Norway spruce (Pinus a ~es w IC oes no now extend beyond 69t0 N · . . Fossil plants closely resembling those JUSt ~ent1~ned have been found at many other Arctic localities, es~ec1ally m Iceland, on t h e Ma c 1{ enz1·e R1'ver 1'n 65° N · Lat· and m Alaska. As an m· terme d1' a t e st a t1'on we have , in the neigh. bourhood of Dant.z ic 1· n L at. 55o N ., a similar flora ' with the swamp-cypress, sequo. ias, oaks, poplars, and some cinnamons, laurels, and fig~. A ht.tle f ur th er south , near Breslau north of the Carpathians, a. nc.b flora has been found allied to that of CEninghen, but wantmg m some of the more tropical forms. Again, in the Isle of M~ll in Scotland, in about 56~0 N. Lat., a plant-bed ?as been discovered containing a hazel, a plane, and a sequoia, apparently identical with a Swiss Miocene species. We thus :find one well-marked type of vegetation spread from Switzerland and Vienna to North Germany, Scotland, Iceland, Greenland, Alaska, and Spitzbergen, some few of the species even ranging over the extremes of latitude between CEninghen and Spitzbergen, but the great majority being distinct, and exhibiting decided indications of a decrease of temperature accordina to latitude, though much less in amount than now exists. So~e writers have thought that the great similarity of the floras of Greenland and CEninghen is a proof that they were not contemporaneous, but successive; and that of Greenland has been supposed to be as old as the Eocene. But the arguments yet adduced do not seem to prove such a difference of age, because there is only that amount of specific and generic diversity between the two which might be produced by distance and difference of temperature, under the exceptionally equable climat: of the period. We have even now examples of an equally w1de range of well-marked types; as in temperate South America, where many of the genera and some of the species range from the CHAP. IX.] MILD ARCTIC CLIMATES. 179 ------- Straits of Magellan to Valparaiso-places differincr as much in latitude as Switzerland and West Greenland ; and the same may be said of North Australia and Tasmania, where, at a greater latitudinal distance apart, closely allied forms of Eucalyptus, Acacia, Casuarina, Stylidium, Goodenia, and many other genera would certainly form a prominent feature in any fossil flora now being preserved. Mild Arctic Climates of the Cretaceous Period.-In the Upper Cretaceous deposits of Greenland (in a locality not far from those of the :Miocene age last described) another remarkable flora has been discovered, agreeing generally with that of Europe and North America of the same geological age. Sixty-five species of plants have been identified, of which there arc fifteen ferns, two cycads, eleven coniferre, throe monocotyledons, and thirtyfour dicotyledons. One of the ferns is a tree-fern with thick stems, which has also been found in the Upper Greensand of England. Among the conifers the giant sequoias are found, and among the dicotyledons the genera Populus, Myrica, Ficus, Sassafras, Andromeda Diospyros, Myrsine, Panax, as well as magnolias, myrtles, and leguminosre. Several of these groups occur also in the much richer deposits of the same age in North America and Central Europe; but all of them evidently afford such fragmentary records of the actual flora of the period, that it is impossible to say that any genus found in one locality was absent from the other merely because it has not yet been found there. On the whole, there seems to be less difference between the floras of Arctic and temperate latitudes in Upper Cretaceous than in Miocene times. In the same locality in Greenland (70° 33' N. Lat. and 52° W. Long.), and also in Spitzbergen, a more ancient flora, of Lower Cretaceous age, has been found; but it differs widely from the other in the great abundance of cycads and conifers and the scarcity of exogens, w bich latter are represented by a single poplar. Of the thirty-eight ferns, fifteen belong to the genus Gleichenia now almost entirely tropical. There are four genera of cycads, and three extinct genera of conifers, besides Glyptostrobus and Torreya now found only in China and California, six species of true pines, and five of the genus Sequoia one of which R 2 |