very dumb question on spies

How do you got more spies?

As far as i can see they just auto generate -
When I start getting messages i have had techs poached I would at least like to be able to drop some resource into fixing the problem rather than just wait for a random spy to be generated.

You get a new spy at every era, starting with the Renaissance. You can also get an extra spy for creating the Police Stations National Wonder, I think it's the CIA?

National Intelligence Agency, after you've built a police station in all cities -- one additional spy, plus all spies are leveled up one notch.

And you get one extra spy if you are playing England (homage to James Bond, I suspect).

And doesn't England also get +1 spy at the beginning of the era for a total of two?

EDIT: Arrrgh! Browd = Ninja