In his valuable essay on _The Origin of Languages_ (249), Mr. Horatio Hale discusses a number of cases of invention of languages by children, giving interesting, though (owing to the neglect of the observers) not very extensive, details of each. One of the most curious instances of the linguistic inventiveness of children is the case of the Boston twins (of German descent on the mother's side) born in 1860, regarding whose language a few details were given by Miss E. H. Watson, who says: "At the usual age these twins began to talk, but, strange to say, _not_ their 'mother-tongue.' They had a language of their own, and no pains could induce them to speak anything else. It was in vain that a little sister, five years older than they, tried to make them speak their _native language_,--as it would have been. They persistently refused to utter a syllable of English. Not even the usual first words, 'papa,' 'mamma,' 'father,' 'mother,' it is said, did they ever speak; and, said the lady who gave this information to the writer,--who was an aunt of the children, and whose home was with them,--they were never known during this interval to call their mother by that name. They had their own name for her, but never the English. In fact, though they had the usual affections, were rejoiced to see their father at his returning home each night, playing with him, etc., they would seem to have been otherwise completely taken up, absorbed, with each other.... The children had not yet been to school; for, not being able to speak their 'own English,' it seemed impossible to send them from home. They thus passed the days, playing and talking together in their own speech, with all the liveliness and volubility of common children. Their accent was _German_,--as it seemed to the family. They had regular words, a few of which the family learned sometimes to distinguish; as that, for example, for carriage [_ni-si-boo-a_], which, on hearing one pass in the street, they would exclaim out, and run to the window" (249. 11). We are further informed that, when the children were six or seven years old, they were sent to school, but for a week remained "perfectly mute"; indeed, "not a sound could be heard from them, but they sat with their eyes intently fixed upon the children, seeming to be watching their every motion,--and no doubt, listening to every sound. At the end of that time they were induced to utter some words, and gradually and naturally they began, for the first time, to learn their 'native English.' With this accomplishment, the other began also naturally to fade away, until the memory with the use of it passed from their mind" (249. 12).