i8 



SURGICAL APPLIED ANATOMY. [Chap. n. 



median line from the inferior angle at the fora 

 men magnum to the occipital protuberaiice is es- 

 pecially distinct (the temporary occipital fontanelle 

 of Button). It exists from the beginning of the third 

 to the end of the fourth month of intrauterine life. 

 Meningoceles of the occiput are always in the middle 

 line, and the pi-otrusion probably occurs through this 



Fig. 4. Back View of Abnormal Skulls, showing Occipital and 



Parietal Bones. 

 A, The " os epactal " ; B, parietal fissures ; c, the sagittal fontanelle. 



gap. The gap associated with meningocele may ex- 

 tend through the whole vertical length of the occipital 

 bone, and very commonly opens up the foramen 

 magnum. The lateral or transverse fissures divide 

 the bone into two parts. The upper part is developed 

 from membrane, the lower part from cartilage. The 

 lateral fissures may persist, and may simulate fractures, 

 for which they have, indeed, been mistaken; or they may 

 be so complete as to entirely separate the highest part of 

 the occipital bone from the remainder. The bone so 



