The bubonic plague is not a virus but rather a bacterium called Yersinia pestis (discovered in 1894 by a bacteriologist named Alexandre Yersin) that lives in the bloodstream of rats as an infection irrelevant. It is transmitted from rat to rat through fleas, which we now know are the original carriers of the plague. When a flea bites an infected rat and collects the bacteria, they rapidly reproduce in the flea's digestive tract, forming a mass that does not allow the flea to swallow. The flea begins to starve due to this blockage and bites new rats in the hope of finding food, but unable to swallow the flea vomits what it bit into the bloodstream, along with the bacteria that were in the flea's stomach, thus infecting a new rat. rat. The plague began when fleas frantically searching for food began biting humans and rats, transmitting Yersinia pestis to humans, which unbeknownst to the human immune system manifested itself in the plague (Damen 2014). However, humans can contract the disease not only from flea bites, but also from inhaling the bacteria. In humans the disease can manifest itself in three ways: bubonic, septicemic or pulmonary. In bubonic plague (which was more common during the Black Death) the lymph nodes in the neck, armpit, and groin swell and blacken, forming "buboes" that then infect the rest of the body. The common practice was to burst these blisters, and then the infection typically killed the patient if the disease managed not to. With septicemic plague, the bacterium inhibits the body's ability to clot, causing internal bleeding that kills the patient. In pneumonic plague, the bacterium settles in the victim's lungs and within four to five days the lungs liquefy, killing the patient. With pneumonia......center of paper......Jews have gone viral." Jspace.com. Np, March 28, 2013. Web. February 10, 2014."The Black Death: Horseman of the Apocalypse in the 14th Century." The Black Death. Np, nd Web. 08 February 2014. "The Black Death." WordPress.com. Np, 11 December 2008. Web. 8 February 2014. Trueman, Chris. "The Black Death from 1348 to 1350." HistoryLearningSite.co.uk. History Learning Site and Web. 09 February 2014. VanPutte, Cinnamon L., Jennifer L. Regan, and Andrew F. Russo. "Chapter 11: Blood." Essentials of Seeley's Anatomy and Physiology. New York: McGraw-Hill, 2013. No. Print. Wein, Berel. "The Black Death." hemophilia?" NHLBI.NIH.GOV. National Heart-Lung and Blood Institute, July 31, 2013. Web. February 10, 2014. Wilensky, Gabriel. "Blaming the Jews for the Black Death." Six Million Crucifixions. Np, nd Web . 11 February. 2014.