Gromov Vladimir S. RussiaMoscowA. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33 Leninsky Prosp., Moscow 119071, Russiavsgromov@mail.ru Author's articles TERRITORIAL STRUCTURE AND SOCIAL ORGANIZATION OF TWO SUBSPECIES OF THE MIDDAY GERBIL (MERIONES MERIDIANUS NOGAIORUM, M. M. PSAMMOPHILUS) (MURIDAE, MAMMALIA) UNDER SEMI-NATURAL CONDITIONS