Here is how it looked when I bought it. It had only a single short stalk.
The stalk started to spit down the middle as the Xenia grew. One stalk grew a few nubs on it. The split eventually reached the foot of the coral. The stalk with the nubs started to drop down closer to the rock it was on. After a day or two of sitting next to the rock one of the nubs became a foot and grabbed hold of the rock.
The coral now looks like this. The two stalks are now in the process of splitting completely in two.
The taller stalk appears to be starting to split also. Looks like the whole process will repeat itself soon. Some people complain that these things can grow like weeds. I look forward to the day I can prune these and perhaps trade the frags for some different coral.
Meanwhile, my original Xenia has completely disappeared. I examined the rock it had been attached to and couldn't find a trace of it anywhere.