What does a cactus grow from? Recently i repoted a cactus which seems to be growing really nifty....

Recently i repoted a cactus which seems to be growing really nifty. I reused the old soil mixing it up beside new and useing it on another plant.

When watering this other plant (which is not a cactus) i spy a cute litle baby cactus growing beside it after a few months.

Note-when i reused this soil as above in that was beyond doubt nothing contained by it!!!!!!!! Where did the baby cactus come from?

The just thing i can reckon of is they must spore like a mushroom possibly?

Does anybody know the facts on this?

Thankyou Aly.
Answers:    cactus grow from seeds .
the kernel can survive for years before it `grows`
the origional grower of the cactus would own planted the seed which as immediately grown into your cactus.
Baby Cactus :]