The same author has issued a new edition, in abridged form, of the "Memoirs," written, according to him, by Dietrich Tiedemann, of a son of Tiedemann two years of age (the biologist, Friedrich Tiedemann, born in 1781). (_Thierri Tiedemann et la science de l'enfant. Mes deux chats. Fragment de psychologie comparee par Bernard Perez._ Paris, 1881, pp. 7-38; Tiedemann, 39-78. "The First Six Weeks of Two Cats.") But it is merely on account of its historical interest that the book is mentioned here, as the scanty (and by no means objective) notes of the diary were made a hundred years ago. The treatises of Pollock and Egger, mentioned in the periodical "Mind" (London, July, 1881, No. 23), I am not acquainted with, and the same is true of the work of Schwarz (mentioned above, p. 224). Very good general statements concerning the child's acquisition of speech are to be found in Degerando ("L'education des sourds-muets de naissance," 1 vol., Paris, 1827, pp. 32-57). He rightly maintains that the child learns to speak through his own observation, without attention from other persons, far more than through systematic instruction; the looks and gestures of the members of the family when talking with one another are especially observed by the child, who avails himself of them in divining the meaning of the words he hears. This divining, or guessing, plays in fact a chief part in the learning of speech, as I have several times remarked. New comprehensive diaries concerning the actions of children in the first years of life are urgently to be desired. They should contain nothing but well-established _facts_, no hypotheses, and no repetitions of the statements of others. Among the very friendly notes that have been sent to me, the following particularly conform to the above requirements. They were most kindly placed at my disposal by the Baroness von Taube, of Esthonia, daughter of the very widely and honorably known Count Keyserling. They relate to her first-born child, and come all of them from the mother herself: In the first five months I heard from my son, when he cried, all the vowels. The sound _ae_ was the first and most frequent. Of the consonants, on the other hand, I heard only _g_, which appeared after seven weeks. When the child was fretful he often cried _gege_; when in good humor he often repeated the syllables _agu_, _agoe_, _aeou_, _ogoe_, _eia_; then _l_ came in, _uel_.