A focus on amud bet: When the nazir shaves on having become impure via 3 different ways of a dead body rendering one impure. And then the text lists many various parts from the dead body. And then the nazir needs to redo the count of pure days of nezirut. [Who's Who: Rabbi Meir] When critics were bothering R. Akiva - delving into a precise wording of the mishnah - from among the students. When R. Meir dies, R. Yosi is quiet. But he needs to address the topic of the measure of flesh that can cause impurity - from the dead body. Plus, the rivalry among the Tannai - to make sure the right version of the mishnah was disseminated.