Pontecorvo proposed to give lectures in institutions in Moscow, Leningrad and Kiev on somatic cell hybridisation and high altitude ecosystems in sprin or early summer 0f 1972 or 1973. He also planned to spend two weeks collecting and photographing alpine flora in a suitable area of the Tien Shan. The Royal Society were planning on funding his research trip. He was talked out of going to the Tien Shan but was suspicious of the reasons given by his Russian colleagues. He ended up cancelling the trip as he did not want to give up a summer season working on photographing and collections alpine plants for a book he was writing.
In 1977 he was contacted by geneticists in the USSR inviting him to a conference and he decided to have a second attempt at planning a trip there to give a series of lectures and to visit the Tien Shan to do some field work. Again he was told that he could not visit mountainous areas as it was not safe, and again he cancelled his trip.
This series of correspondence demonstrates Pontecorvo's dedication to spend his summers in the alps or mountainous areas doing what he loved most: photographing and collecting plants and flowers that grew there for a book he was writing on alpine environments.