Unquestionably these little ants are tool-using animals, because they make their larvæ serve as spinning spindles and also as weavers’ shuttles. However, this can hardly be cited as a point in common with even the lowest type of man, for the ants merely use the tools they find at their disposal. They certainly cannot be credited with having produced or even improved the tool which they use, whereas even in the most primitive of men we find that the tools used are not only carefully selected for the work to be performed, but are actually, shaped, be it ever so crudely, to suit the job. Clearly we must shift the boundary between man and beast, distinguishing the former as the creature who artificially improves his tools. But even here it is not absolutely certain that the boundary will stand. Wilhelm Boelsche, a well-known German writer on natural history, calls attention to the “blacksmith woodpecker” which will thrust hard pine nuts into cracks in the trunk of a tree, so that they are held as if in a vise, enabling the bird to operate upon the seed more easily. Furthermore, this woodpecker will actually make a hole in the tree to receive the nut if there is not a hole or crack handy, so that evidently this animal does produce or artificially improve the tool that it uses. There are a few such examples in nature, just enough to cast a bit of uncertainty on the boundary we have set. But although the actual line of demarcation may not be clear, there is no question but that the lowest type of humanity now existent, or of which we have any record, is or was a tool maker. Chipped stones evidently fashioned by man for some useful purpose are found even in the remains of the Middle Tertiary Epoch. The spirit of inquiry, of experiment, of invention, and the ambition to dominate over other members of the animal kingdom or over the obstacles imposed by nature, are to be found more or less active among all peoples, no matter how lowly a position they may occupy in the scale of civilization. WAR AS A STIMULUS OF INVENTION The most primitive implements were probably developed for the purpose of war. From the very earliest times, down to the present day, war has been a most potent stimulus of invention. The first tools ever used were probably intended to enable the user to cope with dangerous enemies. They marked the first stage in the conquest of brain over mere brawn. The primitive weapons were used not only in fighting other men, but in fighting off dangerous animals, and then in hunting animals for food. No doubt the first implement ever used was a club, which gave a real advantage over the unarmed, scratching, tearing, and biting enemy. This was a lever which increased the reach of the fighter, and also increased the power of his blow. The heavier the club, the more dangerous the weapon, particularly when most of the weight was centered at the outer end of the stick. But he was a real genius who first fastened a rock to the end of his club.