266 



THE PINEAL ORGAN 



The Vascular Supply of the Pineal System of Sphenodon 



According to Dendy (Fig. 188), there is much individual variation 

 among different specimens of Sphenodon, but the arteries concerned in 

 the supply of the system appear to be always derived from the posterior 



SOC. 



Fig. 188. — The Brain and Pineal System of Sphenodon punctatus. 

 The right side of the skull has been removed, showing the brain and large sub- 

 dural space. The latter is traversed by blood-vessels. The minute pineal 

 eye (0-53 mm.) is seen in the parietal foramen, lying beneath the parietal 

 plug, which is formed of translucent connective tissue. (After Dendy.) 



cerebral artery and all the venous blood is returned via the sinus longi- 

 tudinalis. The posterior cerebral artery divides on each side into an 

 artery to the dorsal sac — saccular artery, and the superior cerebral artery. 

 The superior cerebral artery gives off numerous branches to the hemisphere 



