DRAINAGE AREAS OF THE SKULL 141 



central and lateral foramina of the basi-sphenoid bone, 

 with the foramen magnum of the occipital bone, constitute 



FIG. 57. EXTERNAL BASE OF THE SKULL SHOWN IN FIGURE 56. (A.T.) \. 



i , palate plate of the superior maxillary bone ; 2, palate plate of the palate bone ; 

 3, anterior palatine canal ; 4, is placed outside the posterior palatine canal, inside 

 the tuberosity of the superior maxilla, and in front of the smaller posterior pala- 

 tine canals ; 5, inner surface of the external pterygoid plate ; 6, is placed within 

 the posterior opening of the right nasal fossa on the internal pterygoid plate ; 7, 

 vomer ; X , posterior opening of the pterygo-palatine canal in front of the fora- 

 men lacerum ; 8, spheno-maxillary fissure leading into the orbit : 9, foramen 

 spinosum ; 10, foramen ovale ; 1 1, placed on the apex of the petrous bone, between 

 the foramen lacerum and the inferior opening of the carotid canal ; 12, jugular 

 foramen ; 13, articular eminence of the temporal bone ; 14. external auditory 

 meatus ; 15, glenoid fossa in front of the fissure of Glaer ; 16, tympanic plate or 

 posterior part of the glenoid fossa, close to the styloid process, behind which is 

 seen the stylo-mastoid foramen ; 17, mastoid process, and to its inside the digastric 

 and occipital grooves; 18, basilar process of the occipital bone, and in front the 

 mark of the still incomplete union with the body of the sphenoid bone ; 19, condyle 

 of the occipital bcne ; 20, is placed in the foramen magnum, and points to the 

 inner opening of the anterior condylar foramen ; 21, posterior condylar foramen ; 

 22, jugular process of the occipital bone ; 23, external occipital crest running 

 down from the protuberance ; 24, superior curved line of the occipital bone ; 25, 

 26, inferior curved line. 



the main sewers, so to speak, through which the cerebral 

 lymph circulation obtains a regulated and safeguarded 



