Addison Emery Verrill (1839-1926) earned his Harvard SB summa cum laude in 1862 and an honorary AM from Yale in 1867. As an undergraduate student, he spent much of his time in the study of zoology, spending many hours cataloging specimens in the museum of comparative zoology and joining expeditions. In the summer of 1861, he joined an expedition to Anticosti Island, in the Gulf of the St Lawrence in Quebec. He worked closely with Professor Louis Agassiz. Verrill became Professor of Comparative Anatomy and Entomology at the University of Wisconsin from 1868 to 1870. He was Yale University's first Professor of Zoology, serving there from 1864-1907.
This diary includes information on Verrill's daily activities, health, and study of zoology; it provides only occasional references to current events such as the Civil War. Diary entries are almost daily; each includes a list of activities. A few include drawings of specimens or activities; drawings of activities are chiefly humorous. The drawings were often made on a separate sheet of paper, cut to size and glued into the diary. There are no entries for the summer of 1861, the period of the Anticosti expedition, for which Verrill kept a separate journal.