Francis, "bagels..."
However, the real reason is:
Because, once upon a time, there lived near a small south atlantic island, a particular type of porpoise that never seemed to die of old age. The islanders were used to researchers showing up, and offered them advice on finding these porpoises.
As it was, these porpoises were only to be seen at one time of the year, when fledgling gulls were learning to fly, (those that did'nt make the mark, usually fell into the sea, and were consumed by the porpoises).
Those who attempted to find these porpoises were advised to bring some of these gulls with them, to use as bait. They, the researchers, were instructed to proceed to the cliff, past a pride of sleeping, (usually), lions, and toss their gulls into the sea. One time, however, the lions woke up, and ate the researchers.
The moral of this story? "Never transport young gulls past staid lions, for imortal porpoises". :wink: