ENIn Lithuania the monograph "The Phenomenon of Academician Tadas Ivanauskas" has been published, devoted to the 140th anniversary of the most outstanding Lithuanian biologist, ecologist, professor, social activist, and a builder of the Modern Sovereign Lithuanian State — Tadas Ivanauskas. The monograph presents the life, activities, publications, and remembrance of T. Ivanauskas, representing an entire epoch in the country’s 20th century biology, together with a group of intellectuals having laid the foundations for a modern state, its academia, scientific research in biology and agronomy and a huge number of non-governmental organisations. T. Ivanauskas had strong relations with a lot of scientists and scientific organisations from the Baltic States, especially including Latvia. Keywords: Tadas Ivanauskas, biology, ecology, zoology, modern sovereign Lithuania state, science history.