S. F. Light

Sol Felty Light (May 5, 1886 – June 21, 1947) was an American zoologist, entomologist, and professor at the University of California, Berkeley, known for his research on caste development in termites in the first half of his career, and for teaching marine zoology courses in the second half. From 1913 to 1947, he published approximately 70 papers, most on the subject of entomology. His class syllabus on zoology was originally designed for students at Berkeley, but in 1941 it was published as an invertebrate zoology textbook and field guide that had larger appeal, as it was considered the first complete compendium of marine invertebrates in the north central California coastal region ever published. After Light's death, the book was edited, revised, and expanded by Ralph I. Smith and other contributors, becoming known as Light's Manual. After Smith himself died, the book was renamed The Light and Smith Manual in his honor.

Biography
Light was born in Elm Mills, Kansas, on May 5, 1886. His father was a Presbyterian minister, and his maternal grandfather was United States Senator James W. McDill (1834–1894) from Iowa. Other details about his early life are unknown. Light attended university at Park College, Missouri (AB, 1908). After graduating, he spent time abroad in Asia, teaching for several years in Japan, and two years at Manila High School in the Philippines. He went on to spend two years teaching zoology at the University of the Philippines, where he attended graduate school (MS, 1913), participating in a marine survey at the harbor of Puerto Galera, Mindoro. For about four months, from March to June 1912, Light and a team of researchers, including ichthyologist Alvin Seale (1871–1958), set up a temporary site, collecting samples for the department of zoology. They discovered that the site would be ideal for a permanent station. Bullock notes that Light's early work on coelenterates, octocorals, and true jellyfish arose out of this period in the Philippines, and argues that Light's former students at the university were partly responsible for later helping to establish the Puerta Galera Marine Biological Laboratory in 1925.

Light became a full professor at the University of the Philippines, and finally chairman of the department until 1922. He took a leave of absence and obtained a second masters at Princeton University (MS, 1915). From 1922 until 1924, he chaired the zoology department at the University of Amoy (now Xiamen University) in China. While there, he published an article in Science about lancelet (amphioxus) fisheries, surprising scientists at the time who were unaware of their prevalence in the region, previously believing the fish was rare. George Sarton (1884–1956), the founder of the history of science discipline, was so impressed by Light's paper regarding lancelets that he cited it in his fifteenth critical bibliography of the field for 1924. That same year, Light returned to the U.S. to pursue research on termites, receiving his doctorate under professor Charles Atwood Kofoid on termite flagellates at the University of California, Berkeley, (PhD, 1926). In 1928, he worked with the Termite Investigations Committee, a joint University of California and private industry project to help find the best way to control the impact of the insects. As part of the committee, he served as chairman on the subcommittee on publicity, as vice-chair on biology, and chair on the advisory council. Light's important role on this project was noted by the American Association for the Advancement of Science (AAAS) in late 1929. That same year, Light was made full professor. His contributions to Termites and Termite Control (1934), written in collaboration with Kofoid, and his 1935 study on termite colony castes, established him as an expert in his field.

In the 1930s, Light began teaching marine zoology and holding five-week summer courses and field trips to Moss Beach. From these classes, he developed a syllabus in 1937 which evolved into an invertebrate zoology textbook and field guide, later publishing it in book form as the Laboratory and Field Text in Invertebrate Zoology (1941). The book is recognized as "the first reasonably comprehensive treatment of marine invertebrates" in the north central California coastal region.

On June 21, 1947, Light drowned as he was swimming in Clear Lake, while fishing on summer vacation. Until his death, Light served as professor of zoology at Berkeley for 22 years.

Personal life
Light married Mary Nexbitt Holdcroft on January 1, 1925. He was said to have had a conservative demeanor, always appearing in full business suits while on field trips at the beach, only changing his shoes for rubber boots. Light disliked using "Sol Felty" as part of his full name; Light's students knew him as "Dr. Light", while his own wife referred to him only as "S. F. Light" after he died. Former student Joel Hedgpeth remembers that Light "always signed himself S. F. Light, or S. F. L. He obviously didn't care much for what his parents had done for him...So sometimes, we use those terms, being overfamiliar in our behind-his-back sort of references." Light was quietly active in the Christian community and belonged to the First Congregational Church of Berkeley, where he participated in the role of a vestryman. The church was popular with other members of the zoological community, with Light's doctoral advisor Charles Atwood Kofoid and colleague Richard M. Eakin notable members.

Legacy
In the 1940s, Light was profiled in American Men of Science as one of the top 255 practicing scientists in the U.S., of which he was rated one of a group of 37 top zoologists in the country. During his lifetime, Light published 70 papers, many in the field of entomology. After Light's death in 1947, his colleagues made note of his contributions to academia. "[His] whole life was motivated by great ability, high ideals, strict honesty, and real responsibility that helped to make him the great teacher and investigator that he was", wrote fellow Berkeley entomologist E. O. Essig in Light's obituary. Former student and neuroscientist Theodore H. Bullock, zoologist Richard M. Eakin, and ornithologist Alden H. Miller wrote that Light's "unique courses in marine zoology given at the seashore under difficult conditions...maintained standards of excellence unsurpassed by any center of instruction in marine biology in the country". Hedgpeth recalls that Light was referred to by others as an "inspired pedagogue" who "left his mark on virtually every institution of learning on the Pacific coast."

A notable group of students who studied under Light at Berkeley became leading authorities in their respective fields. These students include Olga Hartman (1900–1974), expert on polychaete worms, professor of biology at the University of Southern California; zoologist Mildred Stratton Wilson (1909–1973), who like Light before her, focused on copepods as a research associate of the Smithsonian Institution and the University of Alaska; Joel Hedgpeth (1911–2006), professor of oceanography at the University of California, San Diego; zoological systematist Paul L. Illg (1914–1998), associate curator at the National Museum of Natural History and professor of zoology at the University of Washington; neuroscientist Theodore H. Bullock (1915–2005), a pioneer in neuroethology; and Donald P. Abbott (1920–1986), professor of biology at Stanford University and teacher at Hopkins Marine Station.

Light also sat on the thesis committee for notable scholars. William C. Reeves (1916–2004), arbovirologist and professor of public health, recalls that during his Berkeley dissertation committee in 1943, the graduate dean chose Light to sit on the thesis committee as a "wild man", someone who could ask the candidate anything. Reeves had never taken any courses from Light, but had heard he "had a reputation for being a very difficult man". After the stressful experience, for which he earned a PhD in medical entomology and parasitology, Reeves came away with the impression that Light was a kind man.

The zoological literature cites Light's research as an example of a historical body of work that contributed to an attempt to find answers to open problems in the study of termites. In 2010, Hanus et al. referred to Light's work on identifying insect pheromones in the reproductive inhibition of termites as part of a larger body of "pioneering studies", of which research continues to this day. A few months after Hanus et al. published their findings, Matsuura et al. summarized the state of modern research in this area of inquiry, pointing to Light's research: "In termites, which evolved eusociality independently of Hymenoptera, the existence of queen pheromones inhibiting the differentiation of supplementary queens has been suggested for many decades, but to date no active compounds have been identified."

Light's Manual
Before Light's death, he acknowledged that the Laboratory and Field Text in Invertebrate Zoology (1941) was both incomplete and in need of corrections. When Light died, the first edition of the book was unavailable to students, as it was out of print. Editing and revisions were needed before it could be republished. Ralph I. Smith (1916–1993) spent years editing and revising the original book, eventually publishing the second edition in 1954 with the title Intertidal Invertebrates of the Central California Coast, and the subtitle "S. F. Light's 'Laboratory and Field Text in Invertebrate Zoology'". Revisions to the new edition were made by Smith, Frank A. Pitelka, Donald P. Abbott, Frances M. Weesner, and other contributors. A third, expanded edition was released in 1975, with the new title Light's Manual. After Smith died in 1993, the title of the fourth edition, published in 2007, was changed to The Light and Smith Manual in his honor. The expanded and revised fourth edition includes coverage of California and Oregon with contributions from 120 scholars.

Collections

 * American Museum of Natural History
 * California Academy of Sciences

Selected publications



 * Books
 * Termites and Termite Control (1934)..
 * Laboratory and Field Text in Invertebrate Zoology (1941)..
 * Articles
 * "Termites of Western Mexico" (1933)..
 * "Termites of Southeastern Polynesia" (1936).
 * "Experimental studies on ectohormonal control of the development of supplementary reproductives in the termite genus Zootermopsis (formerly Termopsis)" (1944)..

Notes and references
Notes

References