Morse rapidly became successful in the field of zoology, specializing in
malacology or the study of molluscs. In 1864, he published his first work devoted to molluscs under the title
Observations On The Terrestrial Pulmonifera of Maine. In 1869, he was elected to the
American Academy of Arts and Sciences. Between 1869 and 1873 he published a series of papers on the embryology and classification of the group. Whereas in 1865 he had accepted the majority view that placed brachiopoda within the molluscs, in 1870 largely on the basis of embryological observations, he proposed that the brachiopoda should be removed from the molluscs, and placed within the
annelids, a group of segmented worms.
Helen Muir-Wood has given an account of the history of the classification of the brachiopods that places Morse's work in its historical context. From 1871 to 1874, Morse was appointed to the chair of comparative anatomy and zoology at
Bowdoin College. In 1873 and 1874 he was a teacher at the summer school established by Agassiz on
Penikese Island. Though the school only operated for a few years, several of its students went on to distinguished careers, including
David Starr Jordan. In 1877, he provided the illustrations for a book by his friend John Mead Gould, entitled
How to camp out. During this period the issue of evolution caused much discussion and controversy. Agassiz was an opponent of evolution. He argued that the persistence of animals such as
Lingula (a brachiopod) over immense periods of time, from the
Silurian to the present day, with little change was "a fatal objection to the theory of gradual development". However all of his students subsequently adopted evolutionary theory in various forms. A clear statement of Morse's position on evolution is found in his address, as vice-president (Natural History) of the
American Association for the Advancement of Science at its Buffalo NY meeting in August 1876 (reprinted under the title of
What American Zoologists have done for Evolution) He adopts a clear
selectionist position, in contrast, for example, to Hyatt, who was a
neo-Lamarckian.
Japan In June 1877 Morse first visited
Japan in search of coastal brachiopods. His visit turned into a three-year stay when he was offered a post as the first professor of zoology at the
Tokyo Imperial University. He went on to recommend several fellow Americans as
o-yatoi gaikokujin (foreign advisors) to support the modernization of Japan in the
Meiji Era. To collect specimens, he established a marine biological laboratory at
Enoshima in
Kanagawa Prefecture. He returned to Japan in 1882–3 to present a report of his findings to Tokyo Imperial University. On his 1882-3 visit to Japan he collected clay samples as well as finished ceramics. He devised the term "cord-marked" for the
sherds of Stone Age pottery, decorated by impressing cords into the wet clay. The Japanese translation, "Jōmon," now gives its name to the whole
Jōmon period as well as
Jōmon pottery. He brought back to Boston a collection amassed by government minister and amateur art collector
Ōkuma Shigenobu, who donated it to Morse in recognition of his services to Japan. These now form part of the "Morse Collection" of the
Museum of Fine Arts in Boston. The catalogue is a monumental work, and still the only major work of its kind in English. He became chairman of the Boston Museum in 1914, and chairman of the Peabody Museum in 1915. He was awarded the
Order of the Sacred Treasures (2nd class) by the Japanese government in 1922. Morse was a friend of astronomer
Percival Lowell, who inspired interest in the planet
Mars. Morse would occasionally journey to the
Lowell Observatory in
Flagstaff, Arizona, during optimal viewing times to observe the planet. In 1906, Morse published
Mars and Its Mystery in defense of Lowell's controversial speculations regarding the possibility of life on Mars. He died at his home in
Salem, Massachusetts in December of that year, of
cerebral hemorrhage. He was buried at the Harmony Grove Cemetery. ==Morse's Law==