The death of Dr. Jacques Rousseau on 4 August 1970 marks the end of an era, at least in French Canada. Scientists of such brilliant eclectism are few and getting fewer every day. He obtained a classical B.A. from the University of Montreal in 1926. He had already begun to attend Brother Marie-Victorin's lectures at the University's Botanical Institute in 1923, and enrolled as a full-time student in 1926 .... He obtained his Licence es Sciences in 1928 and joined the staff as Assistant Professor, teaching genetics, paleobotany and economic botany. ... He completed his D.Sc. in 1934, with a remarkable thesis on the genus Astragalus in Quebec, and became professeur agrege in 1935. ... After the Brother's tragic death in 1944, Dr. Rousseau succeeded him as Director, a post he held until 1956. ... Dr. Rousseau's reputation as an indefatigable field worker is based on his remarkable activities during the summers of some twenty-five consecutive years. He worked in the Lower St. Lawrence and Gaspe Peninsula in the twenties and thirties, crossing the Peninsula on foot in 1931, and giving valuable experience to a large number of field assistants. He worked on the North Shore, in Nova Scotia, and in the Magdalen Islands. In 1942, he crossed Anticosti on foot twice. During the summers of 1944 to 1947, and the winter of 1948 he worked at Lake Mistassini. In 1947, he travelled by canoe down the George River to Ungava Bay. In 1948, he canoed up the Kogaluk and down the Arnaud rivers, via Payne Lake, leading the first group of white men in this particular area. In 1949, with botanist Rene Pomerleau, he explored the Otish Mountains; it was on this trip that he suffered the first of a series of heart attacks that were to stop him ... twenty-one years later. In 1951, he explored Adloylik (Abluviak) Fjord on Ungava Bay, the Korok River and a part of the Torngat Mountains; he also flew to the New Quebec Crater (Chubb Crater). In the summer of 1965, he participated in an archaeologicalinvestigation of the Michea site at Payne Lake: this was his last long field trip. ...Beginning in 1923 he was active in more than 70 different scientific associations, in the fields of botany, geography, history, linguistics, anthropology, folklore and human genetics .... He was a prolific author. His curriculum vitae and bibliography is a mimeographed document of over 85 pages, listing 550 texts, plus over 100 abstracts of papers he read at different scientific meetings. ... In the thirties, he was the most important of Marie-Victorin's collaborators in editing the monumental Flore laurentienne, writing the general identification key and three of the chapters. In his more than 40 years of activity, he described 130 botanical species, varieties or forms, and 8 botanical entities were named after him. From 1945 on, a large portion of his writings were concerned with Northern Quebec ethnobiology. He originated the concept of the Hemiarctic Zone, between the Subarctic and the Arctic, characterized by a mixture of tundra and boreal forest areas. ... There are few persons in the university world today who could claim to have had such a permanent - and quiet - influence in the student world. ...