In the center of what Berthold?
In the center of the leaf sprout
Could anybody observe if the plant is pruducing some liqiud in the center while sprouting the flower?
Some do, same for the Phrag Eric Young from the EYOF, and I have a besseae like that ( even on not yet mature growths)... I still have some plants like that here. The crown is full of water, you remove the water, and you end up the next day with more water. I have no idea why some plants do so, but it is nothing really to worry apparently. The leaves and flower spikes expand normally, at least for my plants.
It is very interesting. It can be a liquid including enzyme to digest insects or other protein like some carnivores do.