The note was signed, “The last one to go.” The obvious humanity and the mention of American marine biological laboratories appealed to a US Naval officer who passed the note on to the MBL. It was later published in Time Magazine under the headline, “Appeal to the Goths”. Dan's scientific work focused on using marine invertebrates as model organisms to study fundamental questions in cell biology and embryonic development. He and his students focused on direct observation of cell behavior using light microscopy and discovered many of the fundamental aspects of fertilization, development, and morphogenesis (e.g., Dan and Okazaki, 1956). To settle a long-standing debate over the existence of the mitotic spindle, he encouraged his student, Shinya Inoue, to construct polarized light microscopes and look for evidence of organized polymer networks in living cells. And, together with Daniel Mazia, he was the first to isolate the mitotic apparatus and subject it to biochemical study. This work demonstrated conclusively the existence of the mitotic spindle and initiated the modern biochemical study of mitosis. Dan and his students also developed methods for measuring small, local movements of the cell surface during division. This enabled detailed, quantitative studies of the process of cell cleavage (cytokinesis). Based on this work, Dan proposed the novel idea that cell cleavage is driven directly by elongation of the mitotic spindle. That is, the spindle itself attaches to the cell surface via 'astral rays' (microtubules) and physically draws in the cleavage furrow (Dan, 1943). Subsequent work indicated that cleavage is actually driven by contraction of an actin filament network in the cortex rather than by expansion of the spindle but this idea was the forerunner of the current view of cytokinesis, in which interaction of spindle microtubules with the cell cortex determines the position of the cleavage furrow. Katsuma Dan was professor of zoology at the Tokyo Metropolitan University from 1949-1968. He also served as president of the university from 1964 until his retirement in 1972. Dan was president of both the Zoological Society of Japan and the Japanese Society of Developmental biologists. In 1976 he received the Second Order Imperial Medal, and in 1987 he received the Emperor's Award for Cultural Merit. A fellowship honoring Katsuma and Jean Clark Dan was established in 1979 for cultural exchange between the United States and Japan. Katsuma Dan died in 1996 in Osaka, Japan, at the age of 91. References