Complex sentence: Carr-Saunders remained a year at Oxford as a demonstrator in comparative anatomy but left in 1910 to University College London where he studied biometrics under Karl Pearson.
Split into simpler sentences: Carr-Saunders remained a year at the University of Oxford as a demonstrator in comparative anatomy. He left in 1910 to join the University College London where he studied biometrics under Karl Pearson.