various slaves in the tantradox ' dominion , siamese twin beasts and demons , wearing a myriad of spiked-leather harnesses , saddles , yokes , straitjackets , and other such bondage devices , some leading others on leashes and studded collars , attended to their master and mistress like midwives and wet nurses , walking in single file along the arete of the crane 's arm to reach them , scrabbling over the gigantic womb itself , or being raised from the sides of the fiendfarms on circular platforms adorned with yin-yang symbols .