These three are more closely allied to each other than any of the previous ones. They are also nearer the Keltic; so much so, that a single class has been made out of the four, a class called Indo-European. The study, however, of the _value_ of classes is in its infancy. The real fact that they are allied to an extent to which the others are not, is important. Such are the _existing_ groups; but when we consider how small is the number of the Basques, the only present representatives of the great Iberian class, and that their preservation to the present time is mainly due to the accidental circumstances of their occupancy of a stronghold in the Pyrenees, a new series of facts is suggested. The likelihood of stocks now extinct having once existed, presents itself; and with it, a fresh question. The same suggestion arises when we look at the country occupied by the intrusive families of the Osmanlis and the Majiars of Rumelia and Hungary. The populations here are comparatively new-comers; yet it was no uninhabited tracts that they appropriated. Who was there before them? Perhaps some members of one of the stocks now existing. Perhaps, a wholly different family now extinct. Again--the displacements effected by the different European populations, one with another, have been enormous. See how the Saxons over-ran England, the Romans Spain and Gaul. How do we know that some small stock was not annihilated here? History, it may be said, tells us the contrary. From history we learn that all the ancient Spaniards were allied to the ancestors of the Basques, all Gaul to those of the Bretons, all England to those of the Welsh. Granted. But what does history tell us about Bavaria, Styria, the Valley of the Po, or Ancient Thrace? In all these parts the present population is known to be recent, and the older known next to not at all. The reconstruction of the original populations of such areas as these is one of the highest problems in ethnology. To what did they belong, an existing stock more widely extended than now, or a fresh stock altogether? My own belief is, that the number of European stocks for which there is an amount of evidence sufficient to make their extinction a reasonable doctrine, is two--two and no more; and, even with these, the doctrine of their extinction is only _reasonable_. _a._ The old Etruscans are the first of these; _b._ The Pelasgi the second. Each will be noticed in its proper place. I have used the word _extinction_. I must now qualify it; reminding the reader that this very qualification introduces a new and difficult subject. Extinction often means no more than the abolition of the outward and visible signs of ethnological difference. A negro marries a white. In the fourth, fifth, sixth, or seventh generation, as the case may be, his descendant is, to all intents and purposes, a white man. Yet the negro blood is not extinguished. It exists, though in a small proportion.