From Prisoners to Royalty all knelt to receive the Eucharist on the tongue.
Princess Grace receiving Holy Communion
Story: That night the little girl came back. Slipping past the guard at the priest’s house, she went inside the Church. There she made a holy hour of prayer, an act of love to make up for the act of hatred. After her holy hour she went into the sanctuary, knelt down, bent over and with her tongue received Jesus in Holy Communion, since it was not permissible at that time for laymen to touch the Sacred Host with their hands.
The little girl continued to come back each night to make her holy hour and receive Jesus in Holy Communion on her tongue. On the thirty-second night, after she had consumed the last and thirty-second host, she accidentally made a noise and woke the guard who was sleeping. He ran after her, caught her, and beat her to death with the butt of his rifle. (Story from Archbishop Sheen)
Now: Casually received by all in the paw:
Besides having the odour of Sacrilege, it diminishes belief in the Real Presence (the only real “accomplishment” of allowing it). It’s also bad for Ecumenism with our Seperated Brethren (Orthodox, not the Protestants) , See: