Carefully take out a few of the little black dots .. dry them also carefully between soft paper and put them on top !! of a pot with a soil-sand-mixture, do not cover with soil ! .. they need light and sunlight to start life - put some glass or transparent plastic over it and water the soil from the bottom ...place the pot into sunlight and in a few days or 1-2 weeks you will see the first green small leaves -- yes in the beginning they have leaves .. within a few weeks they will grow fast enough that you can put them in seperate pots .. and what you finally get you can see on the pics .. a Hylocereus undatus .. with wonderful big white flowers with a strong smell .. and -- its hard to kill that kind of cactus .. just dont let him freeze and do not overater him !