Cinda, From observation of the crested forms I have like those pictured here, what seems to happen is the growing point of a small rosette gets doubled, triple, etc. On the young ones, you can often see multiple structures that look like small rosettes jammed up against each other in a line. The plants grow laterally duplicating this, eventually curving back in on themselves. Crested forms growing this way frequently die off, as eventually the growing ends of the plant curve completely under, either pushing the roots away from the soil or not getting enough light to the growing areas to continue growth. This appears to be one of the growing 'styles' that you see with the crests, and I believe it is likely the most common form. The Mauna Kea crests that I have grow this way.
If you take one of these "circular crests", and cut it in half perpendicular to the line you see down the center of the plant, you can then plant both pieces, which will root and continue to grow. This does, however, have the potential to cause the crest to grow in different ways. I have one crested plant that grows laterally across the surface of the soil so far, not curving.
Janice's 'Cebenese' crest looks to me like it is close to the point will it will start to deteriorate because the curvature is taking the growth points under the soil. It is a critical time for these types of crests. Peter has lots more experience with these than I though I've been spending a lot of time watching mine since I've started to get interested in them. My observations are only preliminary as aI need to see more examples and what they do over time.
