Abstract
ON MARCH 18, 1943, the very active two-and-a-half-year-old son of a surgical colleague fell from his high chair with such force that his head bounced on the floor. He seemed dazed for a moment or two but had no definite period of unconsciousness. He cried loudly for a few minutes, as one might expect, but soon seemed to forget all about the fall and was apparently as well as ever. He ate his supper with a good appetite, and was put to bed. Two hours later he began to vomit; he was very pale and his skin was moist and . . .