LAVRENTEV 214 



division of vegetation of European-Asiatic Steppe Regions. He 

 investigated zoning and compiled vegetation maps. His work on 

 the history of flora and vegetation threw light on the origin of 

 vegetative cover of the U.S.S.R. He introduced the concept of 

 phytogeosphere as a part of the biosphere. 

 Bibliography: 



History of flora and vegetation of U.S.S.R. according to the 

 data of the contemporary distribution of plants. Vegetation 

 of the U.S.S.R. (Collection of Articles), L Moscow- 

 Leningrad: 1938, 235-296. 



Steppes of the U.S.S.R. Vegetation of the U.S.S.R. (Col- 

 lection of Articles), 2_. Moscow-Leningrad: 1940,1-265. 

 On the phytogeosphere. Questions of Geography, Moscow, 

 1949, #15, 53-66. 



Age of botanical regions in non-tropical Eurasia. Izvest. 

 Akad. Nauk S.S.S.R., Ser. Geog., Moscow, 1951, #2, 17-28. 

 and V. B. Sochava, eds. Steppes and agricultural lands in 

 the steppe regions. Vegetative Cover of the U.S.S.R. 

 Explanatory text to *'Geobotanical Map" of the U.S.S.R., 

 Scale 1:4,000,000. Moscow-Leningrad: 1956, 595-730. 

 Office: V. L. Komarov Institute of Botany of USSR Academy 



of Sciences 

 Ulitsa Popova, 2 

 Leningrad, P-22, USSR 



LAVRENTEV, MIKHAIL ALEKSEEVICH (Mathematician) 



M. A. Lavrentev was born November 19, 1900 in Kazan. In 

 1922 he graduated from Moscow University. He received the 

 Doctor of Physical-Mathematical Sciences degree in 1933 and 

 the Doctor of Technical Sciences degree in 1932. From 1931 to 

 1941, he was professor at Moscow University. He was made 

 Chairman in 1934 of the Department on Theory of Functions at 

 the Mathematical Institute of the U.S.S.R. Academy of Sciences. 

 From 1939 to 1948 he was Director of the Institute of Mathe- 

 matics and Mechanics of the Ukrainian S.S.R. Academy of Sci- 

 ences, and from 1945 to 1948 he was Vice President of this 

 Academy. Lavrentev was Director of the Institute of Exact 

 Mechanics and Computing Techniques of the U.S.S.R. Academy 

 of Sciences from 1950 to 1953. He was, in 1951-53 and in 1955- 

 57, Academician Secretary of the Department of Physico- 

 Mathematical Sciences of the U.S.S.R. Academy of Sciences. 

 In 1957 he became Vice President of the U.S.S.R. Academy of 

 Sciences and Chairman of the Siberian branch of the U.S.S.R. 

 Academy of Sciences. He was elected Academician of the 



