Saturday, Mama cat carried her one kitten down to floor level into Fluffy's box containing the other 3 older kittens, and began to care for all of them with Fluffy watching nearby. Apparently, this is what is happening, that both queens are now working together to care for their collective broods. I believe Mama cat is the instigator of this activity however, as she appears to have a super-mom kitten-caring personality.

............wayne