Final answer:
The context of what Jeffrey stopped doing is not clear, and without additional information, it is not possible to provide a specific answer.
Step-by-step explanation:
The question "What did Jeffrey STOP doing altogether?" lacks context, which is essential to provide a specific answer. This question could relate to a variety of subjects, and without additional information, it's impossible to determine what Jeffrey stopped doing. For a more accurate and helpful response, additional details are needed regarding the subject matter being referenced, such as a book title, historical event, or a scientific concept if it pertains to Jeffrey's actions within those contexts.