May 13, 1909] 



NA TURE 



■ — if, indeed, any theory is legitimate. As we have 

 already indicated, we are of opinion that Dr. Gaskell's 

 theory is fatally condemned because, as he says, it 

 makes the assertion that what was hypoblast in the 

 arthropod has become ppiblast in the vertebrate, and 

 what was epiblast in the arthropod has become 

 hypobla-^t in tlie vertebrate. But Dr. Gaskell 

 thinks that the germ-layer theory argues in a 

 vicious circle, and he practicallv throws it over- 

 board — which we are not prepared to do. Yet this 

 makes criticism very difficult. 



Xo one can read this book without being impressed 

 with the author's audacious ingenuity, with his 

 patient following up of clues into remote recesses, and 

 with the good humour with which he holds his tinus 

 contra muiidum position. Whether he is right or 

 wrong, he has written an entertaining book and 

 found out a lot of interesting things by the way. We 

 cannot pass from the book without feeling the pre- 

 cariousness of pedigree-construction and the need for 

 some re-statement of the principles of morphology. 

 Perhaps we should also recall the fact that if it be 

 impossible to attach the vertebrate phylum with even 

 plausibility to annelid or arthropod or any other stock, 

 a more modest inquiry remains — How, from what 

 we know of invertebrates, can we concefve of the 

 origin of the various characteristic vertebrate features? 

 To this inquiry, which seems to us more promising 

 and profitable than the search for a lost pedigree, we 

 think that this fascinating book has made several 

 noteworthy contributions. 



AN INSULAR FLORA. 

 Botany of the Faeroes. Based upon Danish Investi- 

 gations. Published by the aid of the Carlsberg 

 Fund. Vols. 1-3. Pp. .xxviii + 1070 ; illustrated with 

 24 plates and 202 figures in the te.\t. (Copenhagen 

 and Christiania : Glydendalske Boghandel, Nordisk 

 Forlag; London: John Wheldon and Co., 1901- 

 igoS.) 

 A NV addition to our knowledge of the natural 

 ■^^ history of the islands on the north-west fringe 

 <if Europe must be welcome. Most people know 

 little more of one such group— Faeroe Islands—than 

 that they are somewhere in the North Atlantic 

 Theie are eighteen islands in all, lying, mostly more 

 or less befogged, in 62° N. lat. and 70° W. long., at 

 the meeting point of a warm Atlantic current with 

 a cold polar one from the east coast of Iceland. They 

 are nearer the .Shetlands (300 kilos, distant) than 

 Iceland (480 kilos, distant). They are all basaltic in 

 origin. The basalt occurs in horizontal beds, con- 

 tains 10 per cent, of lime, and weathers easily. 

 There are 15,000 people and 100,000 sheep on them. 

 Their mountains are 3000 feet in height, and are still 

 unexplored for the most part. The average annual 

 temperature is 65° C, the winter being mild, and 

 summer cold, with rapid changes. There are 23 per 

 cent, dry, 12 per cent, calm, and only 5 per cent, clear 

 days in the year. 



In the work before us. Prof. Warming and his 

 Danish colleagues have given, within the limits of 

 NO. 2063, VOL. So| 



1 100 octavo pages, in an excellent English transla- 

 tion, with very few slips, a model survey of the 

 flora of the islands, on the practical completion of 

 which (begun in 1806) they are to be congratulated. 

 Not the least valuable feature in the publication is 

 the large series of beautiful illustrations, some of 

 which, reproduced on a larger scale in the " Vegeta- 

 tionsbilder " of Karsten and Schenk, are the best 

 photographs of marine algee the writer has seen. 



The many contributions to the report do justice to 

 the work of Lyngbye and other early investigators. 

 After a short historical introduction by Warming, 

 Ostenfeld devotes a hundred pages to the description 

 of the geology and physical geography of the islands. 

 We are reminded of the island of Heligoland, which, 

 like the Faeroes, is being worn away on its west 

 and north-west coasts by the sea, so that, in both 

 cases, in the course of time the islands will disap- 

 pear. In the case of the Faeroes subsidence is con- 

 tributing to this result. 



In a short review it is impossible to do more than 

 mention the work of the various experts. In the 

 lists of each group there are valuable notes accom- 

 panying many of the species, as well as general 

 conclusions and comparisons with the distribution of 

 the same group in Norway, Iceland, and Scotland. 

 The comparison with the flora of the Shetlands, espe- 

 cially of the lower groups of plants, is vitiated by 

 the incompleteness of the information available. In 

 one case the Danish observer visited the Shetlands 

 to collect the information needed for the comparison. 



Broadly speaking, the conclusion on each group of 

 plants studied is that the islands have such a flora 

 as their geographical position would lead one to 

 expect — a touch of the subarctic tvoe found in Iceland 

 and North Scandinavia, with, in the main, the tem- 

 perate-European and Atlantic types. The hawkweeds 

 (twenty-one species and two varieties) examined by H. 

 Dahlstedt are all endemic ; half of them are of the 

 Atlantic type, and post-GIacial in origin. The vascular 

 plants are dealt with by C. H. Ostenfeld, who, in 

 vol. i., treats of their distribution, and in vol. iii. 

 makes a valuable contribution to plant-ecology. This 

 account has been also issued as a separate work, and 

 includes an account of Raunkiaer's biological types, 

 which are based on the selective adaptation of plants 

 bv bud protection to unfavourable climatic conditions. 

 There are 298 vascular plants (flowering plants and 

 ferns), and of these 90 per cent, are herbaceous peren- 

 nials. There are no trees on the islands, and only 

 fourteen species at all woodv. Two of these are 

 Dryas octopetala and Salix licrbacca. The illustrations 

 (e.g. that on p. 904, showing how the hapaxanthic 

 Cochlearia officinalis becomes perennial) are excellent. 



C. Jensen describes in his enuineration of the 391 

 forms of Bryophyta one new species, Pohlia faeroensis, 

 and many new varieties. Sphagnum is well repre- 

 sented, and peat occurs on nearly every island. There 

 is also some coal of inferior quality. The lichens, 

 220 species as listed by Branth, are generally stunted, 

 due in part to competition with the mosses which 

 thrive in the moist climate, and in part to the strong 

 winds and the browsing sheep. E. Rostrup records 



