forms of "them" or "it" ?

I was working on Metes, and I was assaulted by a muse...which suggested
something.  I'll give a few examples so it is as clear as I can make it:

"Mark(1) told about a beetle(2) that lays its_eggs(2) in buried dung(3).
After a month or so, it(2) emerges from the ground."

the name for this verbal phenomenon(sp) may be obvious, but I don't know it.
  its a way of specifying (through the use of suffixes or prefixes attached
to an otherwise ordinary noun) *which* noun  is being refered to in a
follow-up sentance.

Rodney(1) shot the lion(2) in the tree(3).  He(1) then ran away.

Rodney(1) shot the lion(2) in the tree(3).  It(2) then fell.

Rodney(1) shot the lion(2) in the tree(3).  It(3) then fell.


was that clear?  I hope it was; but if not, I'll clarify to the best of my
ability.