It's not unusual for the New Yorker cartoonists to make fun of their own sponsors, but here's my personal favourite:
If you're too lethargic and constipated to click on the picture for a larger view, he's saying "Yeast eater!" This an unquestionable reference to the advertisements for Fleischmann's Yeast, a ridiculous 1920's cure-all that I've been posting about occasionally.
You might be amazed to learn that Fleischmann's Yeast is still being sold, though no longer as a curative...people just bake bread with it nowadays.
You might also be interested to hear that Peter Arno -- originator of the "Whoops Sisters," who flounced through The New Yorker from 1925 to 1927 -- was also married to Lois Long, and somehow I think they both deserved each other.