514 Journal of Comparative Neurology and Psychology. 



Fig. 6. Anomalous arrangements of arteries shown by Cases 2159, 2163, 2169 and 2177. 



Fig. 7. Case 1926. Semidiagrammatic sketch of the circle of Willis viewed from the left, partly in 

 profile, showing the point of origin of the anomalous branch from the internal carotid artery and its junc- 

 tion with the basilar. By the origin of the basilar branches it will be seen that the basilar artery is 

 represented by three portions which have been designated upper, middle, and lower portions, and that 

 the vessel is very irregular in caliber owing to the junction with the abnormal branch, and the unusual 

 origin of the cerebellar arteries. 



