I20 



NA TURE 



\May 30, 1878 



exhibited on p. 300 of vol. i. (see Fig. 2), which will 

 give the reader some idea as to how snow-blindness may- 

 be produced, and which might have reminded Capt. 

 Nares that the expedition was provided with the instru- 

 ment we speak of. When the sun reaches a certain 

 height, above 14°, during clear weather, "the most 

 brilliant prismatic colours are displayed by each minute 

 snow-prism, and in combination form a sparkling arc on 

 the snow-covered ground, the bright light from which ^ 

 too powerful for the unprotected eye. The * diamond-dust^' 

 as we term it, becomes more open as the length of the radius 

 is increased. Consequently, when the sun is between 

 fourteen and twenty-three degrees in altitude, the refrac- 

 tion of its rays is set forth with the greatest effect, and 

 snow-bhndness has to be guarded against. In the bright 

 arc, while each tiny prism displays its complete set of 

 colours, the red tint is the most prominent nearest the 

 Bun, the purple lying on the outside indistinctly defined." 

 We regret that such observations were so rare, and that 

 so little use was made by the expedition under Capt. 

 Nares of the fine set of apparatus for physical observa- 

 tions with which it was provided. This is the weak point 

 of the expedition, and, so far as physical science is con- 

 cerned, the "Arctic Manual" need hardly have been 

 written. The 26th paragraph of the sailing orders runs : 



Fig. 2.— Diamond Dust. 



"The most approved instruments have been furnished to 

 you for the purpose of pursuing research in the several 

 branches of physical science, and as certain of your 

 officers hare been specially instructed in the modes of 

 observing, you will take care to give them every fair 

 opportunity of adding their contributions thereto." Very 

 few " fair opportunities " seem to have occurred to the 

 expedition. 



But after all it is doubtful if the commander of the 

 expedition is so much to blame. The truth is that the 

 instructions to the expedition said more than should have 

 been said about trying to reach the pole. What we 

 wanted and what we still want are steady continued 

 observations of meteorological and other phenomena in 

 the polar area. The Royal Society might have saved 

 itself all trouble if the instructions had been published 

 beforehand. The comparative meagreness of the scien- 

 tific results is, Ave believe, due more to the tone of the 

 instructions than to Sir George Nares. 



Thanks mainly to Capt. Feilden, however, the expe- 

 dition has not been altogether barren in scientific results, 

 as the Appendix filling half the second volume will testify. 

 With the exception of the short paper on the tides by 

 Dr. Haughton, this appendix deals with the natural 



history and geology of the region visited. Each of the 

 departments of natural history, from the mammalia 

 downwards, has been worked out by a specialist, and the 

 results, though seldom novel, are all highly interesting. 

 Life was found in the sea at the highest point reached, 

 and not far from the same point the tracks of a hare 

 were seen. Dr. Hooker has some important observations 

 to make in connection with the flora brought home, which 

 confirms his previous conclusions as to the essentially 

 Greenlandish nature of the Greenland flora. He is in- 

 clined to think that vegetation may be more abundant in 

 the interior of Greenland than is supposed, and that the 

 glacier-bound coast-ranges of that country may protect a 

 comparatively fertile interior. We are almost driven to 

 conclude, he thinks, that Grinnell Land, as well as 

 Greenland, are, instead of ice-capped, merely ice-girt 

 lands. The geological results are fully and ably dis- 

 cussed by Mr. De Ranee and Capt. Feilden, who indeed 

 traverse summarily the whole ground of Arctic geology, 

 to which their paper is a >^luable contribution. Their con- 

 clusions are essentially the same as those already formed 

 as to the very different climate that must have at one 

 time prevailed in these regions. Dr. Coppinger' s report 

 on the great glacier that discharges into the Petermanit 

 Fjord is interesting, though his observations do not seem 

 to agree entirely with Dr. Hooker's con- 

 clusions. 



On the whole Sir George Nares' s two 

 volumes confirm the opinions we have already 

 " published with regard to this expedition. 



One and all exerted themselves nobly and 

 bravely to carry out the main object of the 

 expedition ; the results, geographical and 

 scientific, brought home are of great value, 

 and repay to a considerable extent the outlay 

 and the hardships endured ; at the same time, 

 now that the full narrative has been published, 

 we must express regret that the scientific 

 results are not more abundant than they are, 

 and that they contrast so markedly with those 

 of previous English expeditions, and with the 

 expeditions of Germany and Austria, where, 

 however, the officers are all trained men of 

 science. Notwithstanding the results we 

 cannot regret that the expedition was sent 

 out ; it has solved the question of Arctic 

 exploration so far that it is clear the Pole is 

 not to be reached by the Smith Sound route 

 — if at all, indeed by any means hitherto tried 

 — unless some line of land be met with that 

 will enable the sledge to be utilised. Meantime this 

 narrative of the last great English Expedition will prove 

 attractive and instructive to many readers. We cannot 

 conclude without saying a word in praise of the many 

 fine illustrations of Arctic scenery, a number of the finest 

 being permanent Woodburytypes. There is also a large 

 map showing the new discoveries, and a special one of 

 Markham' s journeys. 



TRANSPLANTATION OF SHELLS 



TT is well known that animals and plants inhabiting 

 ■*■ freshwater have, as a general rule, a very wide dis- 

 tribution ; yet each river system, with all the pools and 

 lakes in connection with it, seems completely cut off from 

 every other system of the same country. Still more 

 complete is the separation between the freshwaters of 

 distinct continents or of islands ; nevertheless they often 

 possess freshwater species in common. In my " Origin 

 of Species" I have suggested various means of trans- 

 portal; but as few facts on this head are positively 

 known, the case given in the adjoined letter of a living 

 Unio, which had caught one of the toes of a duck's foot 



