It is believed by many people that strong impressions made upon the mother during pregnancy may produce marks or defects in the child. This belief dates from earliest antiquity, and is widespread among all races. The belief particularly refers to the emotions of fright or sudden surprise; thus it is believed that if a woman during pregnancy should be frightened by some animal, the child might carry the mark of the animal upon its body, or it might even be born in the shape of the animal. Thousands of such _alleged_ cases are given in proof. There is hardly a layman, or, particularly, a laywoman, who does not claim to know of authentic cases of maternal impressions. It is a thankless task to try to shatter well-established beliefs, and I do not hope to succeed in persuading all my readers that all the stories and examples of maternal impressions are untrue and lack scientific foundation. But I consider it my duty to state my belief, whether you accept it or not. In my opinion there is not a single _well-authenticated_ case of maternal impression. There is hardly a case of defect or monstrosity where the cause is supposed to be due to maternal impression, which cannot be explained in some natural way, or simply by accident. Thousands of women are frightened or shocked by disagreeable sights, by crippled men, by animals, and still their children are born perfectly normal. On the other hand, many marked, or defective, or monstrous children are born in which no maternal impressions can be given as the cause. So why can it not happen when the mother was frightened by something during her pregnancy, and the child was born with some mark or defect, that the latter was simply an accident and not the _result_ of the impression? Because a thing _follows_ another thing it does not mean that it was _caused_ by that other thing.