NO. 12 JAW OF PILTDOWN MAN — MILLER IJ 



vertebral column by strong muscles ; 1 the anterior maxillary region 

 is not retracted, and the nasal bones are flatly sunk into the interorbital 

 region and the upper border of the nasal orifice. In the Hominidce 

 the peculiar position of the condyles is accompanied by special modifi- 

 cations in the floor of the braincase. The area between the foramen 

 magnum and the choanse is bowed upward, the mastoid process is 

 carried downward and forward until it almost encroaches on the 

 region lying below glenoid notch, and the tympanic plate and entire 

 petro-mastoid are distorted from their primitive form. The temporal 

 bone of " Eoanthropus" (Dawson and Woodward, 1913, pi. 19, fig. 

 2) shows by its exact resemblance to the same bone in Homo that this 

 fundamental part of the skull was completely adjusted to the task of 

 supporting a human brain in the upright position. Belief that a 

 primate like the One to which this temporal bone belonged, and living 

 as recently as the late pliocene or early pleistocene, lacked that cor- 

 responding balance-adjustment in the maxillary region which is pres- 

 ent in all members of the Hominidce actually known, cannot reason- 

 ably exist without the evidence of an entire specimen ; yet such 

 absence of mechanical unity between the two parts of the skull must 

 be assumed in order to provide the specimen with a long, narrow 

 upper arch to fit the lower jaw 2 (compare pis. 3 and 4) . Similarly, in 

 the absence of a specimen showing human nasal bones coexisting with 

 the protruding anterior maxillary region of the great apes, there is 

 every reason to suppose that the Piltdown jaw was not closely asso- 

 ciated with this pair of typical human nasals (Dawson and Wood- 

 ward, 1914, pi. 15, fig. 1) until the deposition of the remains near 

 each other in the old river-bottom. It is not improbable that ancient 



1 A peculiar instance of approach to a balanced condition of the head is 

 furnished by the South American monkeys of the genus Saimiri. Here the 

 back part of braincase protrudes so far that the condyles are made to be 

 nearer the middle of the skull than in any other monkey that I have examined. 

 There is no indication of a general readjustment of the skull, the base of 

 braincase together with the facial region remaining as in related genera. 



2 As the cranial floor between the temporal bone and the median line is not 

 represented by the fragments it is perhaps not safe to assume that the dis- 

 tance from one glenoid to the other was as great as in recent Homo. Every 

 feature of the specimen makes it appear probable, however, that such was 

 actually the case. If this human widening existed, the articular surfaces of 

 the corresponding jaw, to accord with the conditions present in all other 

 known primates, should have been wide apart, the jaw should have been 

 strongly arched, and the lower toothrow should have begun to bend inward 

 behind the premolars. Neither the teeth nor the horizontal portion of the 

 Piltdown mandible present any such characters. 



