During the early 1970s McKenna developed a technique for cultivating psilocybin mushrooms with his brother Terence .
They published what they had learned in a book entitled Psilocybin - Magic Mushroom Grower 's Guide .
During the early 1970s McKenna developed a technique for cultivating psilocybin mushrooms with his brother Terence and they published what they had learned in a book entitled Psilocybin - Magic Mushroom Grower 's Guide .