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In 1964 he accepted an invitation to spend the spring semester as guest professor at the University of Hawaii-Manoa, and in 1965, after spending a year teaching and doing research at the University of Baroda (India), he returned to Hawaii and served two terms as the Chairman of the UH-Manoa Zoology Department.
He held a number of Visiting Professorships: University of Rochester, USA, 1958–1959; Kiel University, University of Osnabrück, 1977; University of Baroda, Jadavpur University, 1978; University of Ottawa, 1981.