Who is Narrator of "Tallis" from Ape and Essence and what is their importance?

The narrator of "Tallis" is employed at a movie studio, where he works with Bob Briggs. One day, after he and Bob have lunch, the narrator finds and saves "Ape and Essence" by William Tallis. The next Sunday, when Bob and the narrator travel to Cottonwood Ranch to meet William Tallis, they learn that he died six weeks earlier.