Stacked Quads wiring question

I am about to finally have a set of stacked Quad speakers. The gentleman I am buying them from says they are wired in series. I'm confused about this, as I *assumed* that they had to be wired in parallel. After some research on the Internet I discovered that there are three ways to wire stacked Quad 57 speakers. Series, Parallel, and one amplifier per speaker (ie: four mono blocks or two stereo amps). Putting the last option aside for now, can someone explain how you can wire a set of speakers in series? I know a little about electricity, and know enough about Ohms law to know the effect on resistance when wiring two resistors in series (add the resistance up) vs: wiring two resistors in parallel (final resistance is half the value of one of the resistors assuming both the same value). I realize speakers deal with variable resistance, or impedance as the resistive load to the amplifier changes with frequency. I also have heard that electrostatic speakers have a more capacitive load then traditional speakers. That being said, I still don't see how you can wire two Quads in series. Aren't you going through the crossover network on the first speaker which would adversely effect the second speaker wired in series? I'm really confused about this issue and was hoping someone could explain this to me.

I do know that in parallel, you will have a much lower impedance presented to the amplifier, thus driving it harder then if it's wired in series in which case it presents a higher impedance to said amplifier. This alone might make it more desirable to wire stacked speakers in series, but the crossover thing has me wonky!!

Mark