"Whereupon the poem makes obscure and trivial references to a pair of jungle campers who will certainly be forgotten after fifty years (except in Kansas where they were both born): 'Osa and Martin Johnson dressed in riding breeches, laced boots, and pith helmets.' Not a true sentence, notice.
I'd wager a few sevens, even if they could read, as the kid declares she can, would know what 'pith' is or recognize what the noun does to whatever it touches: compresses them, comprises them. What are pithy remarks? That's the trouble with autobiography. You think you are remembering how you were, when what you are remembering is a depiction of your earlier self.
In Worcester both her boredom and her fright are smothered by dull routine. The swollen clothing--galoshes, 'arctics,' and overcoats--as well as the skinnies--lamps and magazines--will naturally clutter the dentist's office, whereas the boots in the Geographic are militarily laced and polished. Although I am old enough to remember these adventurers, I looked them up in an online archive. The pair sits in a dome-like meadow made of confused weeds. Both Johnsons sport smiles and wide-brimmed cowboy hats. Martin is dressed in a rifle." (79-80)

Excerpts from William H. Gass' essay in the October 2011 of Harper's (78-86). The poem discussed here is In The Waiting Room (1967).