wlmartin
Explorer
Well, it does describe the original beholder as "the parent" and the spawn are smaller (plus, they are called "spawn") do imply that the beholder spawn are beholder "babies" (well, children any). However, given that procreation methods are such as to bend ones sanity and turn ones stomach, its certain they aren't born the ways mammals or reptiles are. Cloning is certainly one way they could be created (though, I would argue said process does not produce an adult beholder, given the spawn's smaller size and minion status), though by no means the only method suggested by your quote.
My favorite theory is that a beholder inserts a mental image of itself into an unwilling host's brain, along with a pinhole portal to the far realms. Over time, the image feeds on the portal (and the host's psyche), slowly gaining reality. Once its ready it becomes solid, and, exploding the host's head, is born.
The idea I like is that the Beholder creates a summoning circle and brings a virgin into its chamber. It torments her mind with images of insanity and after about 30 seconds and then she comes back to where she came from. About 9 months later she is summoned by the same beholder and forced to give birth to a little beholder baby.
... or how about this? You get a bag of holding, put another bag of holding inside it and then another one inside that... you turn it inside out and out pops a baby beholder..... MUAHAHAHAHA