According to the wiki article on Groucho, when they were doing vaudeville, Harpo did originally play an Irish stereotype, pairing Chico’s Italian one. Groucho originally played a German stereotype, but dropped it during WWI:
So Harpo’s silence was suggested by avuncular Al, not a nod to Harpocrates, the great and quietly mighty god of up-shutting. After 43 years, that question is finally put to bed. Occam’s razor strikes again - it *is *the simplest explanation. Thanks Mr. Piper, for that quote. There was a lot of info in that paragraph I’d never encountered.
Grouchocrates was the author of one of my favorite paraphrases (only because I’m likely to screw it up if I called it a quote): Outside of a dog, a book is man’s best friend. Inside of a dog, it’s too dark to read. Did he also say “There’s not five minutes of opera I don’t like.”? Maybe that was Casey Stengel or Joe Biden.