Multiple Pics to One serial port

I am new to Pic processors.
I will be programming in PicBasic Pro.
I am using a 18F4550 as the master.
I am using multiple 18F2431's as slaves.
The 18F2431's will collect the data
to be transimited to the 18F4550
thru the serial port.
The 18F4550 will be used to comunicate
to a Windows based system thru USB & VB6.
(HIDmaker FS software)

I was reviewing old posting and noticed
back in 2001 a discussion on connecting
multiple Pics on one serial line.

Does anyone have information on how this is
accomplished?

I can always multiplex the devices to the
18F4550 using analog switches if necessary.

Thank you.

check this thread
http://www.picbasic.co.uk/forum/showthread.php?p=5708