she heard it from a professor of pathology

Well, he was pathological, wasn't he!

The original joke involving Holmes and Watson made the rounds in the US of A with The Lone Ranger and Tonto as the characters.

Another parrot joke for Jackie:

A linguist who was convinced that parrots could understand human speech spent many years training his parrot to understand several hundred English words, but could never get coherent syntax from him. Just as he was ready to admit failure, the parrot squawked, "Look out, the cieling's falling!" Sure enough, a large chunk of cieling came crashing down upon the linguist, striking him dead. The parrot looked down, then said to himself, "Sheesh, he spends ten years teaching me to talk, then when I do, does he listen? Nooooo."