4IO 



NA TURE 



[March 6, 1902 



devoted to an account of the origin and destruction of 

 these bergs, Prof. Chun passes to a consideration of the 

 Antarctic plankton. The Valdivia's researches were 

 made at the height of the summer, when the surface 

 fauna and flora were at their richest. In many respects 

 they resemble those of the Arctic region, the most 

 striking difference being the complete absence of Cer:itium 

 and the rarity of other dinoflagellates, the place of which 

 was taken by immense numbers of diatoms, especially lliose 

 of the genus Chxtoceras. The greatest richness of the 

 plankton was reached at 20-40 fathoms, the poverty of the 

 surface waters being probably due to their lower specific 

 gravity owing to the presence of melting ice. A twilight 

 flora (Schattenflora), such as is found in the lower 

 layers of the surface waters in tropical seas, is wanting 

 in the Antarctic. On December 17, the ship was brought 

 to a stand by the pack-ice some hundred miles north of 

 Enderby Land in 2300 fathoms, and bore away north, 

 west to Kerguelen. tK dredging taken shortly after this 

 showed a rather rich fauna and brought up a glacier- 

 borne boulder of red sandstone, proving that Enderby 

 Land is not of purely volcanic origin. 



The voyage northwards across the Indian Ocean, 

 which was saddened by the death of Dr. Bachmann, the 

 physician and bacteriologist of the expedition, does not 

 appear to have produced any very startling results. After 

 leaving Padang in Sumatra, researches were made on the 

 deep basin (some 1000 fathoms) between Sumatra and 

 the Mentawi Islands. This basin is separated from the 

 open ocean by a ridge of only 400 fathoms, on which the 

 group is situated, and the bottom temperature is therefore 

 higher (5^9 C.) than that outside the islands. At the 

 same time there is a very rich surface flora. Consequently 

 the bottom fauna is e.xtraordinarily rich. In this neigh- 

 bourhood a specimen of Spirula was taken in perfect 

 condition. A short visit to Suvadiva Atoll in the Maldives 

 gives the author an opportunity for some remarks on that 

 group. .Since this visit, however, our formerly scanty 

 knowledge of the Maldive Islands has been so vastly 

 increased by Mr. Stanley Gardiner's expedition that the 

 observations of the Valdivia are deprived of any value 

 they might otherwise have had. Prof Chun's ethno- 

 logical conclusions are not very different from Mr. 

 Gardiner's, but we very much doubt whether the latter 

 author would accept the suggestion that the Maldives 

 are built on a submarine mountain range. On the voyage 

 to Diego (}arcia, the very important discovery was made 

 that the Chagos group and the Maldives are connected 

 by a bank in 1100 to 1500 fathoms, this bank being sun- 

 dered from that on which the Seychelles lie by a narrow 

 channel only. The last section of the voyage in the 

 Indian Ocean, that along the East African coast from 

 Dar-es-Salaam northwards, in 500-700 fathoms, yielded 

 the richest dredgings in the whole cruise. 



At the end of the volume are some chapters on the 

 deep-sea animals captured by the expedition and on 

 general considerations concerning the oceanic fauna and 

 flora. The "catch" was, on the whole, very much what 

 might have been expected, and seems to contain many 

 interesting forms, but few startling novelties. Hexac- 

 tinellid sponges, actinozoa and echinoderms are naturally 

 numerous, and giant forms of ostracoda, cirripedia and 

 larvacea were taken. Deep-sea ctenophores were dis- 

 NO. 1688, VOL. 65] 



covered, and some of the fish are perhaps even more 

 bizarre than those that were already known from the 

 deep sea. Naturally, the collections have not yet been 

 sufficiently examined to enable general conclusions to be 

 drawn from them with certainty, but Prof Chun seems to 

 incline to the view that the bottom faunas of the Arctic, 

 Antarctic, Atlantic and Indian areas entitle them to be 

 considered as distinct regions, in spite of the marked con- 

 vergence between the members of the first pair and the 

 identity of many species in the second. The surface fauna, 

 and especially the surface flora, is much more peculiar 

 in each region than the fauna of the bottom, but that of 

 intermediate depths has a very uniform character in all, 

 and, since many animals pass from the surface to lower 

 layers of the water at fixed times of the year, it is possible 

 to account for the cosmopolitan distribution of certain 

 forms. On the subject of bipolarity. Prof Chun is at 

 present disinclined to pass an opinion. 



To sum up in a few words the results of such an 

 undertaking as the German deep-sea expedition is 

 difficult. But it may, we think, be fairly said that not 

 only have two or three discoveries of the first im- 

 portance been made — such as the soundings in the 

 neighbourhood of the Chagos group and off Walfish 

 Bay, the "tailing off" of the pelagic fauna below 1000 

 fathoms, and the observations regarding Bouvet Island, 

 but a mass of valuable information has been gathered 

 which, when digested and discussed in the light of the 

 facts accumulated by other expeditions, will set forward 

 very notably our knowledge of the biology and physio- 

 graphy of the sea. 



It is impossible to end a notice of this work without 

 referring to the beautiful way in which it is brought out. 

 The print, the margins, the numerous and artistic photo- 

 graphs, and the headpieces quaintly contrived out of 

 representations of sea animals are all beyond praise and 

 can only be made possible in a work issued at the price 

 of the present one by a wide popular appreciation in 

 Germany of the results of the expedition. What sort of 

 public would such a work find in English ? 



L. A. B. 



CHEMICAL ANAL YSIS. 

 Practical Chemistry. By Abegg and Herz. Translated 

 by H. T. Calvert, B.Sc. Pp. xiii-t-iiS. (London: 

 Macmillan and Co., Ltd.) Price 6.f. 



THIS little work, which deals mainly with qualitative 

 analysis, is based upon the principles of modern 

 physical chemistry. The equations representing "reac- 

 tions in solution " are written in the ionic form, thus : — 



Mn"-h2OH' = Mn(0H), 



Fe--fPOi"' = F8P04- 

 This method of representing reactions in solution as 

 being entirely dependent upon the "ions" has its ad- 

 vantages, but it also has certain disadvantages. In 

 most text-books the above equations would be repre- 

 sented by the action of definite salts, as, e.g., 



MnSOj-l-2KOH = Mn(OH)j-HK„S04 . 

 KeClj -(■ Naol I PO< = FePO. -1- HCl -f 2NaCl, 



When expressed in the latter form, students are apt to 



