July 29, 1875] 



NATURE 



261 



the investigation of which I would particularly recommend 

 to persons visiting Aldabra. 



Mr. Salmon states that the male shows himself to be 

 annoyed when the female is disturbed, and there is no 

 doubt that he exhibits affection for her, as was especially 

 evident on board the steamer, when he tried to break 

 out of his cage as soon as he got sight of the female, who 

 was transported in a separate cage. The circumstance 

 that the two animals are a pair, increases the chances in 

 favour of their being kept alive for a lengthened period. 

 And they will be well worth all the care we can bestow 

 on them, as it is extremely doubtful whether we shall ever 

 succeed again in obtaining a pair of full-grown examples. 

 The male is without doubt the largest and most powerful 

 individual of its race, far exceeding in size any of the 

 few other individuals kept in the Seychelles. Nor is it 

 likely that in Aldabra itself a similarly large example 

 should have succeeded in evading the search of the 

 numerous crews which have landed there. 



From the historical evidence given above, it is evident : 



1. That the presence of the Gigantic Tortoises at two 

 so distant stations as the Galapagos and Mascarenes 

 cannot be accounted for by the agency of man, and there- 

 fore that these animals must be regarded as indigenous. 



2. That, although frequently transported by the early 

 navigators to distant and apparently suitable localities 

 (Sandwich Islands, Masa Fuero, and Ceylon), they never 

 established themselves permanently, but there is no evi- 

 dence to show whether this failure is due to an innate 

 inability of the species to become acclimatised when far 

 removed from its native place, or to the destructiveness 

 of the inhabitants of those localities. 



3. That the different islands of the Galapagos group 

 were inhabited by distinct races. 



4. That possibly the animals even of so small a group 

 as Aldabra were differentiated in the different islands. 



5. That although these animals are still lingering in 

 the Galapagos and Aldabra their numbers are yearly 

 diminishing, and that their growth to perfect maturity is 

 interrupted ; that with respect to the races of the Gala- 

 pagos Tortoise, the elucidation of the irdistinctive charac- 

 ters and original distribution, we are, and probably shall 

 be, dependent chiefly on the materials already preserved 

 in zoological museums. 



6. That the Tortoises of Mauritius and Rodriguez are 

 entirely extinct. It is probable that in some museums 

 shells, or even entire animals of these once so numerous 

 races exist, but it will be a matter of great difficulty to 

 trace their origin ; therefore our examination is limited 

 at present to the osseous remains transmitted from the 

 Mauritius and Rodriguez. Albert Gunther 



{To be continued) 



NOTES 



We are glad to hear that both a zoological and botanical col- 

 lector will form part of the retinue of the Prince of Wales, in 

 his approaching visit to India. 



Dr. Vogel (not the photographer of that name), the Director 

 of the newly established " Sonnenwarte" of Berlin, is now in 

 this country. 



The rate of propagation of the recent inundation waves in the 

 south of France has been determined along the banks of the 

 Garonne. It was found to have been no more than two miles an 

 hour in a run of 140 miles in the district where the principal cala- 

 mities occurred. The consequence is that an immense amount of 

 property and life could have been saved if a system of warnings 

 had been adopted. Wise as usual after the event, the authorities 

 intend to establish such a system as is already in operation at 

 Lyons for the Rhone, and at Paris for the Seine. In an article 

 in the July number of Symons's Monthly Mtteorolo^cal Maga- 

 zine, on the French floods, is an interesting calculation which 

 will give Londoners some idea of what a " flood " means. Sup- 



posing we had a flood in the' Thames, it would cover on the 

 south bank, the whole of Battersea Park, Lambeth, Southwark, 

 Bermondsey, and Deptford ; and on the north bank, Fulham, 

 Chelsea, Brompton, Belgravia, Westminster, and St. James's 

 Park ; while, as for the new embankment, a steamer might ply 

 over the top of it 



It is suggested that the unusual violence of the floods on the 

 continent are attributable not only to the abnormal amount of 

 rain and the sudden melting of snow and ice in the mountain 

 districts, but also to the increasing destruction of forests which is 

 taking place in nearly every country. For some years past the 

 violence of the spring and summer floods has been increasing, 

 and it is remarkable that this increase in their force is contempo- 

 raneous with the gradual extinction of forests and woodlands* 

 The existence of forests has a great effect in equalising the distri- 

 bution of water, and in checking the too rapid melting of snow 

 and ice under the influence of the summer heat. At the same time 

 the growth of timber on hill sides prevents the rapid flow of 

 surface-water which takes place where trees do not exist. The 

 question of maintaining forests, instead of destroying them, with- 

 out making provision for the future, is one which demands the 

 serious attention of the governments of every country, and parti- 

 cularly of those countries where, by the existence of hills and 

 mountains, and consequently rapid rivers, the liability to floods 

 is increased. 



We have been informed that during the recent very bad 

 weather there has been an unusual number of icebergs met with 

 in the North Atlantic, and that fogs in Labrador and New- 

 foundland have been extraordinarily severe and frequent. It is 

 to be hoped that some general inquiry into the recent peculiar 

 weather and its accompaniments will be instituted ; no doubt 

 valuable results would be obtained. 



The Austrian Commission to the International Geographical 

 Exhibition has intimated that they intend to present to the 

 French Geographical Society all the books they are exhibiting. 

 As this example will, we are informed, be followed by other 

 Commissions, a magnificent Geographical Library will be one 

 of the results of the meeting of the Congress. 



The work of the Sub-Wealden Exploration is temporarily 

 arrested at 1,672 feet from increasing deposit from the sandy 

 beds. The original problem was dependent on the opinion of 

 geologists that palreozoic rocks would be found at a depth vaiy- 

 ing from 700 to 1,700 feet. So far, however, the strata are 

 mesozoic ; but the latest fossils give some indications of a 

 palaeozoic rock. Much hope is therefore entertained of solving 

 the problem. 



Parts 19 to 24 of the quarto work published by authority of 

 the Lords Commissioners of the Admiralty, on the Zoology of 

 the Voyage of H.M.S. Erebus and Terror, conclude the descrip- 

 tions of the Mammalia by the late Dr. J. E. Gray, F.R.S. ; the 

 Birds by Mr. R. B. Sharpe ; the Reptiles by Dr. A. Gunther, 

 F.R.S. ; and the Insecta by Mr. A. G. Butler. Part 20 is by 

 Mr. E. J. Miers on the Crustacea, and Part 21 by Mr. E. A. Smith 

 on the Mollusca. 



The Rev. E. Ledger, M.A., rector of Duxford, Cambridge- 

 shire, was yesterday elected to the Gresham Professorship of 

 Astronomy in the City of London. Mr. Ledger was a Carpenter 

 and Beaufoy Scholar of the City of London School, and after- 

 wards Fellow and Lecturer of Corpus Christi College, Cam- 

 bridge. He was fourth Wrangler in 1863, and also University 

 Scholar of the University of London. 



An International Horticultural Exhibition and Congress is to 

 be held in Amsterdam in 1876, similar to the one held in 

 Florence last year. A strong committee has been appointed, 



