430 



SCIENCE. 



[Vol. V., No. 120. 



theory much more in detail, and for the first 

 time makes it complete. For this thorough- 

 going treatment of the subject by the chief 

 geologist, the excellent topographic and geo- 

 logic work of Mr. Strong prepared the way. 



Wisconsin is to be congratulated upon the 

 successful completion of a work which in so 

 many other states has had a different issue. 



NORDENSKWLD'S ARCTIC INVESTIGA- 

 TIONS. 



When Baron Nordenskiold retired in April, 

 1882, from the presidency of the Royal acad- 

 emy of sciences at Stockholm, he took for the 

 subject of his address the story of the Zeni 

 brothers. This address was published in 

 Swedish in 1883 ; and in the same year he laid 

 before the Congres des Americanistes, at their 

 session at Copenhagen, three of the early maps, 

 illustrative, as he thought, of an early acquaint- 

 ance with Greenland, posterior to the so-called 

 Northman discovery in the tenth century, and 

 earlier than the period of Columbus. These 

 were the Zeni map of 1380 (1390?) ; a map of 

 1427, found in a manuscript of Ptolemy at 

 Nanc} 7 ; and the Donis map of the edition of 

 Ptolemy, printed at Ulm in 1482. In the Ger- 

 man version of Nordenskiold' s papers, which 

 has recently appeared as ' Studien und forschun- 

 gen,' we have this same Zeni study in a language 

 easier read by most inquirers. Those who 

 believe in the substantial truth of the Zeni nar- 

 rative will find Nordenskiold on their side. 

 He identifies the Frislancl of the stor} 7 with the 

 Faroe Islands, makes the Zeni to have reached 

 Greenland, and identifies the Estotiland and 

 Drogeo of the Frisland fisherman with our 

 American coast from Newfoundland south. 



The botanical portion of the book has been 

 contributed by three writers, — Nathorst, Kjell- 

 man, and Wittrock, — who treat respectively of 

 the former botanical geography of high lati- 

 tudes as indicated by the results of polar re- 

 search, the biolog}' of the arctic flora, and the 

 vegetable life of the naked snow and ice. All 

 of these articles are remarkably free from tech- 

 nicality, and form pleasant and instructive 

 reading, the last being especially valuable be- 

 cause of its full references to the literature of 

 the subject. 



Fossil collections made from time to time in 

 the arctic region, and, for the most part, 

 elaborated b} T Heer, when compared among 



Studien und forschungen veranlasst durch meine reisen im 

 hohen norden. Von A. E. Nordenskiold. Autoriste ausgabe. 

 Leipzig, Brockhaus, 1885. 9+521 p., illustr., 8 pi., and maps. 8°. 



themselves, and with similar collections from 

 Europe, show a remarkable uniformity in the 

 early flora of the entire northern part of the 

 world, until, scattered and driven southward 

 along numerous lines of migration, it has left its 

 descendants mainly on the eastern sides of the 

 two great continents, as Dr. Graj^ has already 

 shown in his history of Sequoia. 



For the most part, the present arctic flora is 

 composed of the descendants of tertiary alpine 

 species, which, wandering from their original 

 homes, — the Alps, the mountains of Greenland 

 and Scandinavia, the Caucasus, and the Altai 

 and Rock} 7 mountains, — were driven back, at 

 the end of the glacial period, to high elevations, 

 or into the circum polar region, by the warmer 

 climate which succeeded . The collections made 

 by the returning Vega party at Mogi, in Japan, 

 are interesting because they indicate a certain, 

 though relatively slight, reduction in tempera- 

 ture in that part of Asia corresponding to the 

 glaciation of America and Europe, though, as 

 is well known, no traces of inland ice occur 

 there. 



The arctic flora of to-day is a most interest- 

 ing subject for study. While the ocean, at a 

 short distance from shore, supports a growth of 

 giant kelps and dark Florideae, which manifest 

 continued activity the year through, vegetating 

 in the short summer, and pushing their repro- 

 ductive processes during the long winter night, 

 the land-plants are all pygmies, apparently less 

 because the} 7 cannot endure the intense cold of 

 winter, than because they do not enjoy sufficient 

 warmth in summer to assimilate enough organic 

 matter for any considerable growth. 



In a region where the average clail} 7 temper- 

 ature for the least cold month of summer is but 

 a few degrees above the freezing-point, and 

 where vegetation is practically limited to about 

 two months of even this slight warmth, interest- 

 ing adaptations are met with on every hand. 

 Annuals are as good as unknown, the season 

 proving too short for the development of their 

 vegetative organs, and the subsequent matura- 

 tion of fruit. The entire flora is practically 

 biennial or perennial ; the plants rapidly push- 

 ing into bloom, like our spring flora, with the 

 first abatement of the cold of winter, yet, un- 

 like the latter, barely fruiting, and elaborating 

 material for the next year's flowers before the 

 short summer is succeeded by another winter. 

 Indeed, the season is too short for the majority 

 of even these precocious and hardy plants, 

 many of which are forced to rely on vegetative 

 reproduction except in the most favored situa- 

 tions, while nearly all are caught in the midst 

 of flowering by the cold of autumn, which 



