John -- The essay appeared in the July 1906 issue of HARPER'S MONTHLY. It is digitized online at: https://babel.hathitrust.org/cgi/pt?id=uc1.c087222515;view=1up;seq=255 Scroll to p. 221. The essay was also collected in the 1917 edition of WHAT IS MAN? AND OTHER ESSAYS. Barb