Birdie M., 14 years old, we saw after some clever detective work had proved her to be the girl who in another town had repeatedly swindled shop-keepers. It seems she had been accustomed to take the train for localities where she had no connections whatever, and there enter shops and make away with whatever she could. An astounding incident was when she returned some goods she had stolen and persuaded the manager to ``refund'' her the money on the same. This was regarded by the authorities as extremely clever. We found Birdie very small for her age. Weight 76 lbs.; height 4 ft. 8 in. Tonsils very large. Teeth excessively crowded. No sensory defect. Not yet menstruated. A very nervous type; quick physical and mental reactions; exceedingly active, restless manner. Our psychological impressions state that Birdie did all her tests brilliantly and quickly, but very often with less accuracy than would have been the case had she taken the time to think quietly rather than work rapidly. She was very keen to make the best possible record. ``I am proud of being quick; nothing is hard for me; it was not hard at school.'' It was found by steadying her that she gave a more accurate performance. We diagnosed her ability as good, but her school advantages had been poor. Otherwise we noted she was a pert, talkative, responsive child, of a distinctly nervous and somewhat unreliable type. Her ideas came tumbling, one on top of another. Under close supervision she was able to control her mental processes fairly well. For instance, on the antonym test, where opposites to twenty stimulus words are called for, Birdie gave them in the remarkably rapid average time of .8 of a second, with only one failure and one error. This is an exceptional record. From this and her unexpected powers of self-control exhibited on some other tests we were obliged to conclude that her aberrational tendencies were not very deep-set. Her mental traits seemed to conform most nearly to the type designated as constitutional excitement, or hypomania. Further observation of the case confirmed us in this first view of it. On the ``Aussage'' or Testimony Test she gave 13 items, all correct, upon free recital. On questioning, 14 more details were added, but 6 of these were incorrect. Of the 6 suggestions offered she accepted none. Birdie immigrated from Austria with her family when she was 10 years of age. She came of a healthy family; all of her grandparents and many of her uncles and aunts are living. We get no history of any insanity, epilepsy, or feeblemindedness on either side. She is one of 7 children, several of whom have had nervous troubles. Two of the children had convulsions in infancy, but then only. One brother at 10 years old is an excessive stammerer and extremely nervous.