In 1933 Marshall entered
Downing College, Cambridge as an Exhibitioner, supported by scholarships from both the
Cambridgeshire County Council and the Board of Education. He gained a double first in the
Natural Sciences Tripos, having read Zoology Part II. As an undergraduate he was interested in
embryology and this led to him being introduced by his professor
John Stanley Gardiner to
E.S. Russell, whose book
The Interpretation of Development and Heredity Marshall had admired. Russell at the time was Director of Fisheries Investigations at the
Ministry of Agriculture and Fisheries and they discussed fish biology but Marshall was set on pursuing his interest in embryology. However, Gardiner advised Freddy to broaden his horizons and introduced him to a Commander Hawkridge who had an office insuring fishing boats in
Hull. Hawkridge was able to arrange berths for Marshall on fishing boats during his vacation, which allowed Marshall to visit the waters off Iceland three times and
Bear Island and the
Faroes once each. It was on these voyages that Marshall was first introduced to the
macrourid fish on which he would become an authority. These trips may have had some influence on Marshall's decision to give up embryology and to apply for a post as a marine biologist in Hull. He had been lodged in unsatisfactory accommodation in Hull and
Jacob Bronowski suggested that Marshall move in to his lodgings. Here Marshall was given the nickname "Freddy" by Bronowski with whom he became friends and also met his landlady's daughter, Olga Stonehouse, whom he married in 1944. During his stay at these lodgings he also made friends with Cyril Lewis, who lived in the next street and, after Lewis moved to
Edinburgh, Marshall stayed with him when he was posted to Hull's northern outpost in
Leith. ==Army service==