A little girl four years old was alone in the nursery with the door closed and fastened when her little brother arrived and expressed a desire to come in. The following was the dialogue:
"I wants to tum in, Sissy."
"But you tan't tum in, Tom."
"But I wants to."
"Well, I'se in my nightie gown an' nurse says little boys mus'n't see little girls in their nightie gowns."
There was a period of silence during which the astonished little boy reflected on the mystery. It was ended by Sissy's calling out: