The other biography—from which we make a few brief extracts—may be taken as the type of an intelligent and curious deaf-mute. He was not placed in an institution until he was eleven years old. During his childhood he accompanied his father on long expeditions, and his curiosity was aroused as to the origin of things: of animals and vegetables, of the earth, the sun, the moon, the stars (at eight or nine years). He began to understand (from five years) how children were descended from parents, and how animals were propagated. This may have been the origin of the question he put to himself: whence came the first man, first animal, first plant, etc. He supposed at first that primæval man was born from the trunk of a tree, then rejected this hypothesis as absurd, then sought in various directions without finding. He respected the sun and moon, believed that they went under the earth in the West, and traversed a long tunnel to reappear in the East, etc. One day, on hearing violent peals of thunder, he interrogated his brother, who pointed to the sky, and simulated the zigzag of the lightning with his finger; whence he concluded for the existence of a celestial giant whose voice was thunder. Puerile as they may be, are these cosmogonic, theological conceptions inferior to those of the aborigines of Oceanica and of the savage regions of South America, who, nevertheless, have a vocal idiom, a rudimentary language? To sum up. That which dominates among the better gifted, is the creative imagination: it is the culminating point of their intellectual development. Their primitive curiosity does not seem inferior to that of average humanity; but since they cannot get beyond representation by images they lack an instrument of intellectual progress. ANALYTICAL GESTURES. The question of signs is so closely allied to our subject—the evolution of general ideas—that we must insist upon the language of gesture as an instrument of analysis, before going on to speech—of which it is an imperfect substitute. St. George Mivart (_Lessons from Nature_) gives the following as a complete classification of every species of sign, omitting those that are written: 1. Sounds which are neither articulate nor rational, such as cries of pain, or the murmur of a mother to her infant. 2. Sounds which are articulate but not rational, such as the talk of parrots, or of certain idiots, who will repeat, without comprehending, every phrase they hear. 3. Sounds which are rational but not articulate, such as the inarticulate ejaculations by which we sometimes express assent to or dissent from given propositions. 4. Sounds which are both rational and articulate, constituting true “speech.” 5. Gestures which do not answer to rational conceptions, but are merely the manifestations of emotions and feelings. 6. Gestures which do answer to rational conceptions, and are therefore “external” but not “oral” manifestations of the _verbum mentale_.