After reading the text accomoanying the chart, I wondered who this guy was who came up with the stuff. Googled Professor P S Cutter and got the following which I will also pass without comment.
Long time reader, sometime contributor. The reference to Prof G.P. Hartwell is interesting because it echoes the IUSS History on this site contending that Project Hartwell was named for the University of Pennsylavania's Prof G.P. Hartwell. On the other hand, Wikipedia documents that Project Hartwell was named for the Hartwell Farms restaurant in Lexington, MA (near MIT). More likely Hartwell is being confused with G.P. Harnwell, former Penn President (see link)who was a distinguished underwater acoustic scientist.