UNDER this title M. Venoukoff has just published an interesting paper on those parts of Europe and Asia which remain yet unexplored. It is not to be wondered at that the name of Europe should be among incompletely explored parts of the world, as there are even in Europe considerable spaces, especially in the Balkan peninsula and in North-Eastern Russia, which await scientific exploration. The war of 1877-78 certainly afforded occasion for surveying and mapping wide spaces in Bulgaria and Eastern Roumelia, but the geography of Macedonia, Epirus, and even of Thessaly is far from being exact. In Russia all the northern provinces, from the Norwegian frontier to the Ural Mountains are only known superficially; we know here only the coast and the three principal rivers—the Onega, the Dwina, and the Petchora. The great Samoyede tundra remains quite unexplored. Notwithstanding several journeys in the Northern Ural, this country is little known, and the interior of the great double island of Novaya Zemlya remains quite unknown, both affording, however, a very great interest, especially for geologists. As to the hydrographical exploration of the Kara Sea and of the Arctic Ocean north of Siberia, M. Venoukoff does not give them much of importance, notwithstanding what he terms the pompous newspaper writing about the trade with Northern Siberia, and he thinks that there are on the Asiatic continent several places far more interesting for explorers. For instance, Chekanovsky's and Nordenskjöld's explorations have quite changed our ideas on the geography of that land, twice as wide as France, which belongs to the basins of the Khatanga and of the Anabara. It would be a rich field of exploration for a bold traveller. The lands east from the Lena remain quite unknown, and the northern slopes of the Stanovoi Mountains are still a tabula rasa; the sources of the Indighirka, Kolyma, Omolon, Aniouy, and Ghijiga rivers were never visited by Europeans, and Wrangel mapped them only from hearsay. The land of the Chukchis is better known, thanks to the work of the explorers of the last century, to the recent Russian expeditions, and to Nordenskjöld's information; but all our knowledge of this country is far from being exact, and Europeans have never penetrated to the interior of the peninsula which separates the Arctic Ocean from the Pacific, and which promises to have a future as a meeting-point for the whalers, as well as for the trade in mammoth bones. The land of the Koriaks is less attractive, except for a naturalist. As to Kamchatka, certainly it is passably well known, but what a mass of work remains to be done in mapping the west coast, preparing a map of the interior, studying the most interesting geology, botany, and ethnography of the peninsula! Further south we see that the northern part of Sakhalin remains quite unexplored; the Sikhota-alin Mountains are all but unknown; and the regions between the Ussuri and Sungari Rivers, the sources of the Nonni and Argoun Rivers promise very much to the naturalist and to the geographer who would study them. The interesting peninsula of Corea will certainly be explored as soon as access to it is not forbidden to Europeans. In the Chinese Empire there are spaces as wide as England which remain unexplored. As to Eastern and Northern Thibet we are not yet sure as to what is the true source of the Brahmaputra and of the Irawaddi, and what is the importance in the orography of this land of the Kuen-Lun range. The inaccessible deserts of Eastern Turkestan are as deserving of exploration as Thibet, and the reaching of the sources of the Hoang-ho is one of the desiderata of geographical science. The great desert of Gobi is passably well explored, but still there remains an important problem: Does there exist, under the 42° and 43° N. lat., a chain of mountains which crosses the desert and unites the eastern Thian-Shan with the In-Shan Mountains? In northern Mongolia there still remain unknown the highlands at the upper parts of the Selenga River. In China proper there is certainly no room for geographical discoveries, but there remains very much to do as to astronomical determinations, and the substitution of a true picture of nature for the hypothetical chains of mountains which cover our maps. Useless to speak of what might be done with regard to the ethnography of Western and South-Western China. A most attractive exploration would be certainly that of Indo-China in all directions, but it is to be feared that such an exploration will remain for a long time a simple dream, because of the political institutions of this terrestrial paradise. But the exploration of Siam and Annam is one of the most necessary geographical desiderata. Without speaking of the Asiatic islands, where so much remains to do, M. Venoukoff points out that British India is certainly one of the best explored countries in the world, and that several parts of Europe are far behind India as to our geographical knowledge of them; but it is not the case as to those countries which are situated to the north-west of India. Afghanistan and Beluchistan await explorers, especially for certain, perhaps the most important, parts of them, as well as Southern Turkestan and the land of the Turkomans, where so much remains to do. Khorassan and Western Persia are quite well known, but Iran remains unknown; of course the exploration of these deserts, as well as of those of the interior of Arabia, would afford very great difficulties and give comparatively few scientific results. But a thorough geographical exploration of Armenia and of Asia Minor is most desirable; and, to finish with Turkey, M. Venoukoff asks if the Straits of the Hellespont and Bosphoms will be seriously explored as to the most important question of the existence of an undercurrent in these straits?