Felix Behrend junior also went to the Herderschule, and passed out of it in 1929, with high distinction, to study mathematics and theoretical physics at the Universities of Berlin and Hamburg. He soon showed himself a pure mathematician of originality and imagination; his first three papers in the theory of numbers were published in quick succession before he was 23 years old. After taking, in 1933, his Dr phil. at the University of Berlin, he emigrated from Nazi Germany in 1934, first to Cambridge, then to Zürich and Prague, where he worked as an actuary in a life insurance company and continued his work in pure mathematics. He took the degree of Doctor of Science at the Charles University of Prague in 1938, but Czechoslovakia became unsafe in 1939, and he returned to Zürich and then to England just before the outbreak of war.
During the brief scare in the summer of 1940 when Holland was overrun by the German armies, Felix Behrend, like most adult male "enemy aliens" in Britain, whether friends or foes of Hitler, was interned, and not long after transported to Australia. At the instance of G H Hardy, J H C Whitehead, and other prominent British mathematicians, his release from internment was authorised before the end of 1940, but he chose not to return to Britain - the journey to Australia on the Dunera had been a harrowing experience - and remained in Australian internment camps. The time spent there was not lost, but gave full play to his great pedagogical gifts; he gave courses of lectures in the "camp university", and awakened an abiding enthusiasm for mathematics in several younger fellow internees, among them Walter F Freiberger, F I Mautner, and J R M Radok. The students were prepared for examinations of the University of Melbourne, without textbooks because none were available: in spite of this, or perhaps because of this, the teaching was highly successful.
Release from internment came in 1942, through the efforts of T M Cherry, and Felix Behrend joined his department at the University of Melbourne as a tutor. There he remained, being successively promoted Lecturer (1943), Senior Lecturer (1948), and Associate Professor (1954). He would have been made a (personal) Professor, but the illness intervened that led to his premature death on 27 May, 1962, at the age of 51 years. He is survived by his widow Daisy, née Pirnitzer, whom he had married in 1945, and their two daughters.
Felix Behrend's sympathies within pure mathematics were wide, and his creativeness ranged over theory of numbers, algebraic equations, topology, and foundations of analysis. A problem that caught his fancy early and that still occupied him shortly before his death was that of finite models in Euclidean 3-space of the real projective plane. He remained productive for much of the two years of his final illness, and left many unfinished notes in which his work on foundations of analysis is continued. A more detailed evaluation of his mathematical work is to be included in a fuller obituary notice, by T M Cherry, to be published in the Journal of the Australian Mathematical Society.
Felix Behrend was, like his father, an outstanding teacher. He took meticulous care over the preparation of his lectures, which were always distinguished by great lucidity and a sense of beauty, and also by a sure feeling for the level of his audience. His students could always rely on his sympathetic understanding of their problems and on his imaginative but sound advice; he gave them unstintingly of his time.
Among Felix Behrend's recreations, classical music ranked high, but much the most important was creative writing. He had as a young man been deeply impressed by the novels of Thomas Mann, and he continued to admire him and to acknowledge him as his master; but in his later writings the influence of Thomas Mann becomes less noticeable, and his style more individual. Most of his essays and short stories were written in German, and circulated privately among his friends. But he also wrote in English, and his last work, completed only shortly before his illness took its final turn, is a book, "Ulysses' Father", published shortly after his death : it is a children's book of very great charm and will, like "Alice in Wonderland", surely captivate grown-ups, too.
I acknowledge with gratitude the help I have received from Mrs F A Behrend and from Dr Hilde Behrend, Felix Behrend's younger (and only surviving) sister, in collecting some of the factual material I have used.