When the Romans first encountered Germans, they were chiefly struck by the great stature, the blue eyes, and the light hair of this inimical race. Tacitus, in alluding to this fact, says that each German exactly resembled his fellow. Although we are familiar with the external appearance of various nations, yet if we found ourselves in the presence of a large number of negroes we should experience an analogous sensation, only by degrees should we distinguish one from the other. In an intensified degree primitive man must have had similar experiences when, first finding himself in a world of which he knew nothing, and of which he understood nothing, the consciousness of what he saw around him was making itself apparent. These early races learnt the meaning of the details of surrounding nature but slowly; their eyes followed the brilliant circle as it moved from one quarter of the heavens to the other; they noticed the fire which came whence they knew not; they heard the crash of thunder, reproduced by the echoes in the mountains synchronising with the devastations caused by the storm. If one man alone had witnessed these terrifying effects in nature, his reason would have tottered from fear; the stones and the herbs of the field could not share his agitation; the death of a man from terror would leave them unmoved. Happily man was not alone, all those around him shared his agitation, and the terror manifested itself on each by signs which each would understand instinctively. This period of semi-consciousness before the full awakening might have been a prolonged one, but physical sensations and necessities multiplied themselves, and were very various and imperative; action was indispensable if privations were to be avoided; and instinct came to their aid. The need of guarding themselves from the burning rays of the sun caused them to provide shelters by interlacing branches of trees; to protect themselves from cold they took the skins of wild beasts to throw over their shoulders; where natural caverns were insufficient for their wants they made themselves refuges in the sides of the mountains; they were forced to light and maintain fires; sharpen stones either for tools or for weapons of defence; the wants of one were the wants of all, and all gave themselves to the task of satisfying them. It is so evident that primitive activity must have been co-operative, that it outrages common sense to picture each man labouring by himself for himself alone. The mental phenomenon known as _intention_, was the common property of all; the mutual sympathy played the part of the electric current of our laboratories, and the inarticulate sounds escaping involuntarily from the lips of each worker, served as a means of communication.