Well the tag name on each volume element of the iMesh instance within a PyNE Mesh is ```ve_idx```. I think of iMesh tags as key-value pairs, meaning that if ```ve_idx``` is tagged with a value of 0, I read it as "This volume element is assigned a volume element index of 0." I also feel that ```i``` is the most common variable used in conjunction with ```enumerate```.

In any case, I think we have more serious API issues to sort out. This PR might not even be what we want. I will be happy to change variable names once things start to fall into place a bit better :)