How long these Aryans had lived united in this their early home it is, of course, impossible to say; but as the tribes and families increased in numbers, a separation would naturally take place. Large associations of clans would move into more distant districts, the connection between the various bodies which made up the nation would be less close, their dialects would begin to vary, and thus the seeds of new nations and languages would be sown. The beginning of such a separation was a distinction which arose between a part of the Aryan nation, who stayed at the foot of the Hindoo-Koosh Mountains, and in all the fertile valleys which lie there, and another part which advanced farther into the plain. This latter received the name _Yavanas_, which seems to have meant the protectors, and was probably given to them because they stood as a sort of foreguard between the Aryans, who still dwelt under the shadow of the mountains, and the foreign nations of the plains. And now, their area being enlarged, they began to separate more and more from one another; while at the same time, as their numbers increased, the space wherein they dwelt became too small for them who had, out of one, formed many different peoples. Then began a series of _migrations_, in which the collection of tribes who spoke one language and formed one people started off to seek their fortune in new lands, and thus for ever broke off association with their kindred and their old Aryan home. One by one the different nations among the Yavanas (the protectors) were infected with this new spirit of adventure, and though they took different routes, they all travelled westward, and arrived in Europe at last.[31]