sentences:  In 1910 he was elected Master of Christ's College, a post he held until his death, and from 1917 to 1919 he was Vice-Chancellor of the University of Cambridge.In 1893, he published "The Zoology of the Invertebrata", which became a popular university textbook.His "Textbook of Zoology", written jointly with Ernest MacBride, appeared in 1901 and was followed by three further editions up to 1920.