About the close of the subsidence eruptions began which are continued to the present by such volcanoes as Taal and Mayon in Luzon and Apo in Mindanao. No further subsidence appears to have occurred after the close of the Tertiary, though the gradual elevation beginning then had many lapses, as is evidenced by the numerous sea beaches often seen one above the other in horizontal tiers. The elevation continues to-day in an almost invisible way. The Islands have been greatly enlarged during the elevation by the constant building of coral around the submerged shores. It is believed that man had appeared in the great Malay Archipelago before this elevation began. It is thought by some that he was in the Philippines in the later Tertiary, but there are no data as yet throwing light on this question. To-day the Archipelago lies like a large net in the natural pathway of people fleeing themselves from the supposed birthplace of the primitive Malayan stock, namely, from Java, Sumatra, and the adjacent Malay Peninsula, or, more likely, the larger mainland. It spreads over a large area, and is well fitted by its numerous islands -- some 3,100 -- and its innumerable bays and coastal pockets to catch up and hold a primitive, seafaring people. There are and long have been daring Malayan pirates, and there is to-day among the southern islands a numerous class -- the Samal -- living most of the time on the sea, yet they all keep close to land, except in time of calm, and when a storm is brewing they strike out straight for the nearest shore like scared children. The ocean currents and the monsoons have been greatly instrumental in driving different people through the seas into the Philippine net.[2] The Tagakola on the west coast of the Gulf of Davao, Mindanao, have a tradition that they are descendants of men cast on their present shores from a distant land and of the Manobo women of the territory. The Bagobo, also in the Gulf of Davao, claim they came to their present home in a few boats generations ago. They purposely left their former land to flee from head-hunting, a practice in their earlier home, but one they do not follow in Mindanao. What per cent of the people coming originally to the Archipelago was castaway, nomadic, or immigrant it is impossible to judge, but there have doubtless also been many systematic and prolonged migrations from nearby lands, as from Borneo, Celebes, Sangir, etc. Primitive man is represented in the Philippines to-day not alone by one of the lowest natural types of savage man the historic world has looked upon -- the small, dark-brown, bearded, "crisp-woolly"-haired Negritos -- but by some thirty distinct primitive Malayan tribes or dialect groups, among which are believed to be some of the lowest of the stock in existence.