114 HUMAN H1STOKY 



which emphasizes the intermediate position of Dubois's famous 

 discovery. 



It is further probable that Pithecanthropus had free use of 

 the arms, the legs having become specialized for progression. It 

 is quite possible that he may have employed tools of wood or of 

 stone, though there is no evidence to this effect. It is farther 

 possible that some rudimentary form of speech may have been 

 employed. The motor centre for speech is found in a particular 

 area of the brain known as Broca's area. This area can be identi- 

 fied in the brain cast of Pithecanthropus, and it is stated to be 

 twice as great as in the apes, but only half as large as in man. 

 1 The undeveloped forehead of Pithecanthropus and the diminutive 

 frontal area of the brain indicate that the Trinil race had a limited 

 faculty of profiting by experience and accumulated tradition, for 

 in this prefrontal area of the brain are located the powers of 

 attention and of control of the activities of all other parts of the 

 brain. In the brain of the ape the sensory areas of touch, taste, 

 and vision predominate, and these are well developed in Pithecan- 

 thropus. The central area of the brain, which is the storehouse 

 of the memory of action and the feelings associated with them, 

 is also well developed, but the prefrontal area, which is the seat 

 of the faculty of profiting by experience or of recalling the con- 

 sequences of previous responses to experience, is developed to 

 a very limited degree.' 1 



Pithecanthropus is thus a form of the highest interest in the 

 history of man. Provisionally, it may be put at the dawn of the 

 Pleistocene. Uncertainty also surrounds the position of the next 

 human remains to be mentioned, which ^consist of a lower jaw 

 from the Mauer Sands near Heidelberg. 2 It is generally agreed 

 that these sands were deposited in a genial epoch, and opinion 

 now inclines to associate them with the second genial epoch. 

 The jaw itself is very simian, scarcely showing any approach to 

 human characters. The teeth, however, are remarkably human, 

 and it is said that in some respects the teeth of existing primitive 

 races approach the simian condition more nearly than do the 

 teeth of the Heidelberg race. The relation of this form to Pithecan- 

 thropus and to those which follow may be left for consideration 

 until we have completed our sketch of human fossil types. 



1 Osborn, Old Stone Age, p. 83. 2 Schoetensack, Der Unterkiefer dea 



H. heidelbergensis. 



