266 ADOLF H. SCHULTZ 



does not explain in a satisfactory manner the extremely rare oc- 

 currence of a true metopic fontanelle in monkeys, together with 

 the relatively frequent appearance of incomplete nasal reduction. 

 On the other hand, the relative frequency of the metopic fon- 

 tanelle in man according to Schwalbe is 15.2 per cent in children 

 up to 1| years, whereas high reaching nasal bones, such as are 

 found in monkeys, have never been described in the human skull. 

 Moreover, it must be borne in mind that the remnants of the 

 fontanella metopica are often situated in the adult high above 

 the nasion. As shown in table 1 , the lowest point of the remnants 

 of the fontanelle is located as much as 27.5 per cent of the frontal 

 arc above the nasion, its middle point, being even higher. If the 

 fontanelle reallj^ corresponds to the original uppermost end of 

 the nasalia, then the latter must have extended between the 

 frontalia high above the orbits and the supercihary ridges. Bolk 

 assumes that the supranasal portion of the frontal suture (supra- 

 nasal field or triangle) — a frequent finding in adults — is the result 

 of the reduction of the nasaha. However, this supranasal suture 

 reaches as a rule only shghtly above the glabella and not, as Bolk 

 supposes, to the level at which the fontanella metopica occurs. 



Rauber ('06) describes the skull of a child with two fontanelles 

 at the frontal suture (fonticulus interfrontalis superior et inferior) 

 which in his opinion had become separated from the frontal arm 

 of the anterior fontanelle. The fonticulus interfrontahs inferior 

 corresponds to the metopic fontanelle, and as a factor in its 

 remaining patent Rauber considers it possible that the site of the 

 anterior neuropore of the medullary canal of vertebrates exerts 

 its influence under special circumstances, even to the ossification 

 of the skull. 



Schwalbe ('01) in contrast to the explanations offered by pre- 

 vious authors, considers it possible that the metopic fontanelle 

 is to be conceived as a progressive variation, which bears a rela- 

 tion to the greater development of the frontal lobe of the cere- 

 brum. The adult skull described in this paper would seem to 

 support this theory inasmuch as its capacity was 1520 cc. and its 

 smallest frontal width was 109 mm. Both these measurements 

 are rather large for the negro; on the other hand Fischer's cases 



