Weird black kind of prints on perlite

[grib]

This is the 2nd flush after the dunk procedure. Just a few shrooms have grown out of the cake and on the 4th day I found kind of black dust prints on the perlite layer. Looks a bit scary... Shroomies were growing like mad, each is bout 6 inch long (15 cm). I fanned them this morning and no prints were there.
What are the prints? Can the shrooms be dried and used as usual?
I'm going to dunk the cake again.
It's impossible to attach the picture here and the gallery is gone.

[anno]

Black(dark purple actually) prints are the spores of the P. cubensis.

>Can the shrooms be dried and used as usual?
Yes.

Next time you should make some prints. Read http://www.fungifun.org/English/SporePrinting

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