No you do not need them to run the router.
Flash memory PC cards or PCMCIA cards
A Flash memory card that is inserted in to a Personal Computer Memory Card International Association (PCMCIA) slot. This card is used to store system images, boot images, and configuration files.
The following platforms contains PCMCIA slots
The Cisco 3600 series routers include two PCMCIA slots
Because the Cisco 3600 series and Cisco 7000 family can boot images and load configuration files from several locations, these systems use special ROM monitor environment variables to specify the location and filename of images and configuration files that the router is to use for various functions.
Some ciscoFlash MIB variables support the Flash file system on the Cisco 7000 family.
Note that the internal Flash and the Flash memory card cannot be used as a contiguous bank of Flash memory.
J.Fisher CCNA
Jeter@LasVegas.com