SYSTEMATIC SYNTHESIS OF TISSUES INTO ORGANS. 209 



288.* THE CRANIUM is USUALLY SAID TO BE COMPOSED 

 of eight bones, in which two bones only are considered 

 as double, and the rest are looked upon as single. The 

 parietal and temporal are usually so distinct at mature 

 years that they could not be counted otherwise than 

 double; but during growth, and sometimes in mature 

 years, the suture up the middle of the frontal bone is 

 distinct, and at an earlier period all the bones are dis- 

 tinctly double. 



FIG. 161. 



Fig. 161 represents a side view of the skull, with the bones slightly 

 separated. 1, Frontal; 2, Parietal; 3, Occipital; 4, Temporal; one not 

 numbered, in front of 4, Sphenoid ; one faintly represented below 8, Eth- 

 moid; 5, Nasal ; 6, Molar; 7, Superior Maxillary ; 8, Unguiform; 9, Infe- 

 rior Maxillary. Between 3 and 4 is seen a small bone, several of which are 

 apt to be found in the course of those sutures, or seam-joints. They are 

 named Ossa-triquetra. 



289. THE BEST CLASSIFICATION OF THE BONES OF 

 THE CRANIUM, being most philosophical, is that which 

 makes twelve of them, six right and six left ; for some 

 of the sutures are obliterated early, others later, and 



288. How ? Describe Fig. 161. Which bones are shown, tho right or left? 

 289. What is ? 



