Poking around on the web, we see that a modern organization called Sigma Phi Sigma is the "National Morticians Fraternity." Perhaps the owner of this photo wasn't a very skilled dentist, or was moonlighting after clinic hours? A more tantalizing possibility is raised by the history of the Oregon State University chapter of Phi Kappa Psi fraternity, which notes that
Our chapter first started in 1913 as a local Fraternity called the Orange Club. After which it became part of the Sigma Phi Sigma Fraternity until World War 2. During the war, the majority of Sigma Phi Sigma men joined the war effort and the Fraternity dissolved, upon returning from the war, the Sigma Phi Sigma men at Oregon State found Phi Kappa Psi to embody the same principles they had practiced and petitioned for membership. After a few years, they were finally established as the Oregon Beta Chapter of Phi Kappa Psi in 1948 in a ceremony that initiated all living and willing Sigma Phi Sigma Alumni of the chapter into Phi Kappa Psi.Was our dentist (and let's assume he was a dentist, given the book's subject) an early member of this OSU fraternity? Until we get more information, this little snapshot will be placed into the Historical Image Collection under Places > Fraternity Houses.