As we have no reason to suppose that the Australian continent was peopled at a later date than other parts of the world, and as there is no evidence upon that continent of the people inhabiting it having ever been in a higher state of civilization than they are at present, we have grounds for supposing that they must have remained stationary, or have progressed very slowly, while the inhabitants of other parts of the globe advanced more rapidly, and that their existing arts and implements, simple and primitive though they be, nevertheless represent the highest development of constructive power to which these people have ever attained. Hence it follows, that if the inhabitants of any other portions of the globe can be traced to a common origin with the Australians, viewing the persistency of type observable as a characteristic of the arts of these people, and of all other people in a primitive state of culture, we must expect to find some traces of similar implements in use amongst all such people to whom a common origin can be assigned.
In my last lecture I mentioned that there were three countries in which the boomerang is either still used, or is known to have been used in ancient times, viz. Australia, the Deccan of India, and Egypt, and I also showed some grounds for believing that the same weapon, or something allied to it, may have spread from those countries over Europe, as it is known to have done over a great part of Northern and Central Africa.
Although the comparison of weapons from various parts of the globe can have no other object than to trace out an original connexion, I did not venture to build upon the coincidence of this weapon in these regions, any argument for the common origin of the people by whom it was used. Nor do I think that I should have been justified in assuming such origin upon the grounds of the identity of a single weapon. Such identity may have arisen in three ways:--(1) it may have arisen independently by the spontaneous development of like weapons under similar conditions of life; (2) the weapon itself may have been communicated from some primal source; (3) the races using it may have been themselves derived from a common origin. Of these, the first view, viz. the independent origin of the weapon, would perhaps strike any one at first sight, before having studied the conservatism and persistency of type which is so especially characteristic of savages, as the most probable; it appears so exceedingly simple in its form and uses to our trained and educated minds, that it seems hardly necessary to account for it in any other way; besides which, there are slight differences between the Indian and Australian boomerangs, which have been considered by some to distinguish the two weapons.