Aphthous stomatitis (Canker sore). shallow ulcer with a white or yellow center and red border; seen on the inner side of the lip and cheeks or on the tongue; it begins with a burning or tingling sensation and slight swelling; painful; usually lasts 7-10 days and heals without a scar. î î î.
It was all a cheap publicity stunt. One of the regulation features of early ballparks, supposedly, was a gigantic billboard advertising Bull Durham tobacco, inevitably located out in left field, near the pitchers' warm-up area. Hence the bullpen was the pen near the Bull. (Which, frankly, sounds like a lot of bull to me.)
Another popular theory connects the term to an actual bullpen that existed at the Polo Grounds in New York in the late 1800s. Pitchers would use an area near the bullpen to warm up, and so the name stuck. Others claim that the area was originally a place to put fans who bought cheap tickets and that they were herded into the spot like cattle. One of the most likely interpretations simply comes from the cattle industry.