First appearance of Bob's mother. In this episode, her name's Eleanor; in subsequent appearances, her name's Martha.
Bob's mother mentions several times she believes he should've been a cartoonist. Ironically, 20 years later, Bob Newhart played a cartoonist on his 3rd series; Bob (1992).
In this episode, Bob briefly mentions considering becoming a cartoonist. Bob Newhart is a cartoonist in his later series Bob (192-1993)