Well, as it turns out, what’s floating around the internet about Evan being servant to Rowland Davies is WRONG!  I found the reference in Surry County Records, Surry County, Virginia, 1652-1684, pp. 104:

“7 Apr. 1677    Deposition of Rowland Davies concerning Robert Kae touching his Tithables. Kae had four men servants called James Johnson, Jno. Collins, Evan Humhrey, and John Esquire, also one negro woman called Judy, and Kae himself and myself (being Davies) and Kae a son called Robert Kae.
Roger Delke, about 48 years, testified to the same.”

This states that it is the testimony of Rowland Davies about the tithables belonging to Robert Kae.  So Evan Humphries was an indentured servant to Robert Kae; Rowland Davies, only being the witness of the fact.