36 ANATOMY AND PHYSIOLOGY. 



hearing. The two remaining bones are placed at the base of the 

 cranium, and belong equally to it and to the face. The ethmoid 

 or sieve-like bone is so named on account of its upper plate being 

 perforated with forty or fifty holes, through which the twigs of the 

 olfactory nerves pass into the nose. The sphenoid, or wedge-like 

 bone, is named, not from any similarity to a wedge in shape, but 

 from its being wedged in among so many other bones ; for ft is 

 united to the other seven bones of the cranium, and to five of the 

 face. 



The vault of the cranium is smooth and regular where it forms 

 a roof for the protection of the brain ; the floor of it is divided into 

 six pits or deep hollows, for containing the different lobes of the 

 brain. Numerous holes exist in the base of the cranium, for the 

 entrance of the nourishing arteries of the brain, for the exit of its 

 veins, and for the exit of the numerous nerves which are to con- 

 nect the brain with the organs of the senses, and with the other 

 parts of the body. The following figure represents the sutures of 

 the cranium separated, after Beuchene, of Paris. I have a beauti- 

 ful preparation of this kind in my Anatomical Museum. 



Side view of the Cranium. 1. Frontal Bone. 2. Parietal. 3. Occipital. 4. Tem- 

 poral. 5. Nasal. 6. Malar. 7. Superior Maxillary. .8. CJnguis. 9. Inferior 

 Maxillary. 



The shane ot the head, as well as its size, varies greatly in dif- 



