[7] After teaching at San Diego High School for the academic year 1897–1898,[5] between 1898 and 1906 he was an instructor of zoology at the University of Michigan.
[7] At Berkeley, his teaching and research focused on experimental morphogenesis, genetics, animal behavior, and eugenics.
[12] Holmes was a vocal proponent of eugenics, particularly in reference to immigration to the United States from Mexico and parts of Asia.
In 1925, at a major conference on race relations along the Pacific Coast at Stanford University, Holmes told an audience of social scientists and public officials that, "the Mexican problem is by far the greatest race problem which confronts the people of California at the present time.
[2] Their oldest daughter, Dr. Marion Holmes Wagner, became an obstetrician and gynecologist and delivered over 10,000 babies in the San Jose-South Bay area.
[24] Holmes contributed numerous articles to scientific periodicals and journals, and was the author of several books that included:[7][25]