In the flow of mathematical ideas from the West to Central-Eastern Europe one can distinguish several typical forms: 1) foreign mathematicians, invited to cultivate mathematics upon new ground (e.g. Euler in Russia); 2) domestic mathematicians who completed their studies abroad and continued research after returning home (e.g. W. Buniakowski or M. Ostrogradski in Russia); 3) domestic mathematicians who dared developing new directions, thus initiating original schools of mathematics (e.g. N. N. Lusin in Russia). A separate phenomenon was a startling discovery of non-euclidean geometry (N. N. Lobatchevsky in Russia, J. Bolyai in Hungary).