FONTANELLA METOPICA IN AN ADULT SKULL 265 



Adding to these the case of Rauber and that of the author, both 

 of which were males, the total of males is 21, of females 3. The 

 anomaly, therefore, would appear to be of much greater frequency 

 in males. This same preponderance has been found by the 

 author ('16) in another anomaly, namely, the persistent canalis 

 cranio pharyngeus, and this relatively greater frequency has been 

 likewise shown in respect to other anomalies. From this it 

 would seem probable that anomalies are more common in the 

 male, but whether this is a rule for progressive or for atavistic 

 anomalies, or for both, can only be determined when care is taken 

 by investigators to always mention the sex in reporting anomalies. 



Short transverse sutures or fissures occurring in the lower 

 third of the frontal arc in adults have always been interpreted 

 by the various authors as remnants of the fontanella metopica, 

 but the origin of the latter has been explained in widely different 

 ways. The metopic fontanelle was first described by Gerdy in 

 1837. He was followed by Hamy and the Italian scientists 

 Maggi, Riccardi, Staderini and Zanotti. Of these, Hamy ('72) 

 sees in the metopical fontanelle a divergence of the lines of 

 ossification of the tubera frontalia. Maggi ('94, '98, '99) inter- 

 prets the fontanella metopica as a product of the approximation 

 of the four frontalia media. These assumptions are based upon 

 his isolated comparative anatomical observations. Zanotti 

 ('01) explains the medio-frontal fontanelle as the last trace of the 

 foramen, which corresponds to the location of the paraphysis in 

 primitive vertebrates; in other words, a foramen frontale for the 

 paraphysis similar to the foramen parietale for the epiphysis. 

 Both Maggi and Zanotti to a certain extent place atavistic in- 

 terpretations upon the fontanelle, but these must be considered 

 as extremely hypothetical. 



Bolk ('11) w^as led to believe that the fontanella metopica 

 arises at the site of the primitive or primary nasofrontal suture. 

 This opinion was based upon observations on monkeys, in which 

 the nasal bones have become shortened, that is the supramaxil- 

 lary portion of the nasalia is displaced by a medial growth of the 

 frontalia, by which process a secondary naso-frontal suture, 

 situated closer to the apertura nasalis, is formed. This theory 



