- 14 - desert communities. Colchis and Macaronesia were the refugia for mesophytic dendroflora and the immigration of typically Medite- rranean hemixerophilous species was much less marked here. Now we summarize what we know of ecological groupings in the Kodor Flora: the species of the humid subtropical forest floras constitute 30% of this flora, the moist-warm-temperate forest ones 52.9%, the hemixerophytic forest 10.4% and the temperate fo- rest 7.2%. The mountain relief of Colchis and the corresponding zonation of climate and vegetation produced a concentration of the subtropical element (about 1/3 of the whole Kodor flora) in the lower mountain belt, at least, from the Sarmatian up to the Cimmerian. However, even in the lower belt the dominance apparently belonged to the species of humid warm-temperate floras (52.9%). The dry and highly insolated southern slopes in the lower and middle mountain belts favoured the development of hemixerophytic, typical Mediterranean vegetation (sclerophyllous forests). However, judging from the fact that the hemixerophilous element constitutes only 10.4% of the Kodor flora, the features of the Mediterranean climate were not yet well-pronounced at that time. Finally, the temperate forest element, which was then characteristic for the highest levels of the mountains, is represented rather poorly. This can be explained by the temperate forest floras being generally poorer in species while the remains of the plants brought from the mountains are easier destroyed in the torrential river streams and reach the burial sites in the lowlands in lesser numbers. Possibly, similar regularities in the distribution of floristic elements took place on the other shores of the Tethys too. As already noted, in Tertiary time, especially in the Earlier Pliocene, in Colchis subtropical and warm-temperate mesophilous arbor species were abundantly represented, such as: palms, bamboos, species of the family Theaceae (Eucommia), some Araliaceae, species of Carya, Magnolia and many others. In the Upper Pliocene, the majority of them became extinct; the glacier period also played a certain role in this respect. The modern climate of