speaking of. . .
The "petrel and the porpoise" line in 4Q. . . these are two animals who
live a life between, as Eliot knew we lived lives "between."
This assumes that seas are between continents. But couldn't one equally
assume that that continents are between seas? And that subsoil is
between earth core & atmosphere. Then both petrel and porpoise are on
the outside, and giraffes & earthworms are between. :-)
Variations of the image are old -- e.g., "isthmus of a middle state" in
the _Essay on Man_.