The author of the 87th Precinct series presents the story that inspired The Blackboard Jungle and eleven other tales of tough, troubled kids on the city streets.   Inside the concrete walls of Bernard High, brutal young men scrap for survival, fighting with their wits, their knives, and their guns. Brawls are common in the hallways, and more than one student has been carried out on a stretcher this year. Now, Mr. Kemp is the next target. A mild-mannered teacher in far over his head, he's about to be thrust into the middle of a string of muggings happening right inside the school. It's a jungle in there, and Kemp is at the bottom of the food chain.   A tale of animal justice in a school ruled by the power of the switchblade, "The Jungle Kids" is an incredible story. Along with "To Break the Wall," it served as the inspiration for The Blackboard Jungle, the novel about a cutthroat inner-city school that was adapted for the screen and made Ed McBain a household name.   With twelve stories of crime, violence, drugs, and gangs, most of which were originally published in the legendary pulp magazine Manhunt, this collection showcases city life through the eyes of disaffected teenagers. What could be more terrifying?