The line of descent will only pass through these children.

They do not seem to run in particular lines of descent, so I am told.

The Japanese family is based on the line of descent.

A direct line of descent running from them to me.

It appears that the line of descent is through the women.

"How do you know he's in the line of descent?"

Advantage to the species, or, I should say, the line of descent.

There was no line of descent from one to the other.

Don't you think I guard my own line of descent?

It was not uncommon for such titles to continue down the line of descent.