Southwards too, immediately under the snows, we find ` crystalline schists,' smooth grassy heights, separated by shallow trenches, which form the lesser undulations of the three basins, the drei Langenhochthdler Imeritiens of Dr Radde.
Radde's (1831-1903) monographs on Daghestan, quoted at the end of the present article.
Radde, among which the most numerous are migratory birds and the birds of prey which pursue them.
The Siberian branch of the Russian Geographical Society was founded at the same time at Irkutsk, and afterwards became a permanent centre for the exploration of Siberia; while the opening of the Amur and Sakhalin attracted Maack, Schmidt, Glehn, Radde and Schrenck, whose works on the flora, fauna and inhabitants of Siberia have become widely known.