ARTERIES OF THE BRAIN. 385 



branches of some consequence : the Spinalis Posterior, the Spi- 

 nalis Anterior,* and the Inferior Cerebelli. 



The Arteria Inferior Cerebelli divides shortly after its ori- 

 gin, or otherwise is double from the beginning. The mos^pos- 

 terior trunk is distributed about the bottom of the fourth ven- 

 tricle, on the fundamental portion of the cerebellum, and the 

 contiguous faces of the two hemispheres or lobes of the latter. 

 The other trunk of this artery is distributed on the under sur- 

 face of the cerebellum. 



The Basilar Artery (Arteria Basilaris) is on the middle line 

 of the tuber annulare, and extends from its posterior to its an- 

 terior margin. In this course it detaches some arterioles to the 

 tuber; others to the meatus auditorius internus, (Arterise Audi- 

 tivas Internse,) which are spent upon the labyrinth, and anasto- 

 mose with twigs from the internal and external carotids. At its 

 anterior extremity it detaches on each side two considerable 

 trunks ; first the superior artery of the cerebellum, and imme- 

 diately afterwards the posterior artery of the cerebrum. 



The Arteria Superior Cerebelli goes outwardly from its ori- 

 gin just behind the anterior edge of the tuber annulare, until it 

 gains the front margin of the cerebellum. It then divides into 

 several branches, some of which are distributed on the upper 

 surface of the cerebellum and run to its posterior margin, where 

 they anastomose with the branches of the arteria inferior: 

 others are spent upon the substance of the cerebellum near its 

 anterior edge. 



The Posterior Artery of the Cerebrum, (Arteria Cerebri Pos- 

 terior,) one on each side, is the termination of the basilar artery. 

 It proceeds abruptly outwards, and has gdne but a few lines 

 when it receives the arteria communicans posterior of the inter- 

 nal carotid. It then continues outwardly parallel with the an- 

 terior margin of the tuber annulare, and near it crosses the crus 

 cerebri, and is then distributed, on the inferior and on the pos- 

 terior part of the hemisphere and of the corpus callosum. As 

 mentioned, its branches anastomose with those of the anterior 

 and of the middle artery of the cerebrum. 



* See Arteries of Medulla Spinalis. 

 VOL, II. 34 



