During the latter part of the fourth month, the baby was greatly interested in making sounds, and the one that most delighted her was a sort of harsh cawing or croaking, made deep in the throat, on the vowel â. She would lie and utter this sound at intervals, by the half hour, with deep satisfaction. But when she had not been making it for some hours, she was apt to forget just how, and to get it too high or low in the throat, producing an extraordinary collection of squeaks and grunts. She usually hit it at last; but after repeated losings, it became quite dissolved away among the many new ones it had apparently given rise to. Later, she took much pains over some imperfect lip sounds; she would lie looking earnestly at me, draw her breath, gather her lips into shape, and finally explode the sound with a great expenditure of breath. She made her little sounds often with an air of friendly response when we prattled to her, giving back murmurs, croaks, and gurgles for words. From the latter part of the fourth month, if we imitated to her some of these sounds, she seemed to imitate them back. Preyer, who records the same thing of his boy at the same age, thinks it marks a most important epoch, the beginning of action guided by ideas; but Baldwin, who considers the beginning of imitation even more important than Preyer does, thinks it cannot be so early, and that the repeating of the sounds must be mere coincidence. This is likely enough, for a baby is always repeating his pet sounds, and it is not safe to conclude that he means to imitate us, even if he does chance to give back the same sound after us several times. But as to action guided by ideas, we scarcely need wait for the first imitation to see that. It appears in a simple form when the baby first looks for an object out of sight. This our baby had done weeks before, and by this time many of her actions seemed to be of ideomotor type. The effort to recall her croak was an instance. In the early weeks of the fifth month, she would seem to think suddenly of one of her little sounds, and dash at it, bringing it out with a comical doubling up of her body. In the same way she would have the happy thought, “Fingers in mouth!” and up they would come with a jerk, her head diving forward to meet them. In the nineteenth week, she seemed to act once from something like a definite memory. Her grandfather entered the room while she was in her bath, and her usual joyous up and down movement of arms at sight of him produced a novel and fascinating splashing. Next day the baby splashed without suggestion, and again the next, looking up to my face and smiling; and after that no one could teach her anything about splashing. Yet even this was probably not really memory, but an association formed by a single vivid occurrence.