306 PROFESSOR D. J. CUNNINGHAM ON 



respect between the native Australians and the Neanderthal race on the one hand, 

 and of both of these to the chimpanzee and the gorilla on the other hand. 



The Supraorbital Notch and its Relation to the Eyebrow Eminence. 



Schwalbe has pointed out that the supraorbital notch bears an important relation 

 to the eyebrow eminence. A glance at figs. 17, 18, and 19, PI. I., which exhibit the 

 region in the baboon, shows that this notch is the starting-point on the margin of the 

 orbital opening from which the oblique groove, which intervenes between the super- 

 ciliary and supraorbital elements, proceeds. Even in Type III. of this region, where the 

 different elements are massed together with no external indication of their separate 

 identity, Schwalbe takes the supraorbital notch as giving the only clue to the de- 

 markation of the superciliary and supraorbital elements of the eyebrow projection. 

 Schwalbe has failed to appreciate, however, that the supraorbital notches in man 

 and the lower apes are not morphologically equivalent, nor yet similarly placed on the 

 margin of the orbital opening. In other words, the disposition of the frontal nerve in 

 man and the ape is different. 



In man the frontal branch of the ophthalmic division of the trigeminal nerve 

 pursues a straight course within the orbit upon the upper surface of the levator 

 palpebrse superioris, and about midway between the inner and outer walls of the 

 cavity. At a variable point it gives off its supratrochlear branch and is continued 

 onwards as the supraorbital nerve. The supratrochlear nerve inclines inwards towards 

 the inner wall of the orbit, and finally turns round the inner part of the orbital margin 

 above the trochlea of the superior oblique muscle to gain the forehead. As a rule it 

 leaves no mark upon the bone as it winds on to the forehead ; sometimes, however, its 

 path is indicated by a groove, as in the New South Wales cranium (figs. 20 and 21, 

 PI. II.), and at other times it may pass through a foramen, as in the case of the 

 Neanderthal cranium (fig. 3, p. 288, and fig. 6, p. 298). These markings are more 

 frequently present in the crania of lower races, and more especially in those with a 

 projecting glabellar and eyebrow region. 



The supraorbital nerve, or the continuation of the frontal trunk, reaches the forehead 

 by turning upwards in the supraorbital notch or foramen. This notch is variable in 

 position, but usually it lies a little to the inner side of the mid-point of the supraorbital 

 margin. 



Mr Ninian Bruce, B.Sc, has kindly made dissections for me of the orbital cavity 

 in three chimpanzees, one orang, one yellow baboon, and in several species of the genus 

 Macacus. These have shown that the frontal nerve in the ape does not present the 

 same relations within the orbital cavity as is the case in man. 



In the baboon and the macaque the frontal nerve does not divide into two branches 

 within the orbit, but issues from that cavity in the form of one undivided trunk. 

 Further, this nerve courses through the orbit in close relationship to its inner wall, and 



