Greg, what a pity you have never before heard about violas in a humorous context. There are unlimited numbers of viola jokes circulating in a lot of orchestras. Carl Rahkonen,a violist himself, discusses the cause in his paper No Laughing Matter: The Viola Joke as Musician's Folklore. Here he also gives a link to his vast collection of viola jokes. I strongly recommend the reading, it's really fun.

Wilfried