Hullin 126: Dem Bones

The question of impure marrow from bone - if closed, it doesn't matter, but if punctured, it will impart impurity. Thus, bones become a whole discussion unto themselves, as exceptional cases. Also, the eggs of creepy crawlies - when would they render a person impure? (Begin with the perforation of the egg -- much as the hole in the bone to access the marrow makes a difference too). Note: Ahistorical scientific assumptions included. Also, consider the pervasiveness of impurity and the implications of that for society - much like our own.