Transsubstantiation or Consubstantiation?

I've been contemplating the Lord's Supper in recent days. I thought it might be a good time to bring this up.

I Cor 5:
Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?
Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us.

I Cor 10:
For we being many are one bread, and one body: for we are all partakers of that one bread.

John 15:
I am the vine, ye are the branches. He that abideth in me, and I in him, the same bringeth forth much fruit: for without me ye can do nothing. (Jesus spoke this just after the Last Supper and before Gethsemane.)

Matt 18:
For where two or three are gathered together in my name, there am I in the midst of them.