Thank you Adam for this wonderful piece of Darwinian prose!
My interest, too, was pricked by the words uffish, tulgy and boskiness which I have never come across before. So I decided to play a game with myself.
My English master in high school ("Tich" Ferry) was a diminutive chap, a golf and language enthusiast, who lived in Monifieth and played his golf there. As high school students he would set, each week, a task described as Interpretation (aye the 3Rs were extant in days of yore). Defining a few words in the given passage was part of this task. So I drifted back in time and did my best, from the context, to decipher Bernardo's offering of uffish, tulgy and boskiness.
"Longtime in uffish thought he stood" Uffish thought .... deep thought.
"....whiffling through the tulgy wood" Tulgy wood ... scrubland
" ....reasonable tallness and boskiness." Boskiness ..... of thick crown.
How did I go?! I am off to the dictionary after posting this so could have covered myself in literary glory or exposed myself as an illiterate.
Interestingly the auto-correct mode on the Mac created oafish from uffish, tulgy became bulgy and whiffling became whistling. Inexplicably boskiness was allowed to stand uncorrected! Classical education viz a viz language didn't seem to extend as far as computer language! A job for Mark Rowlinson methinks!
Cheers Colin