502 'JoiirJial of Comparatn^e Neurology and Psychology. 



and a few other cases the vertebral was almost or quite inpervious, 

 but in no instance was either vessel absent. 



The Anterior Spinal Artery. — The anterior spinal artery usually 

 shows slight variability in its trunks of origin, depending upon the 

 size of the vertebrals. Occasionally the vessel takes its origin 

 from a short transverse trunk joining the two vertebrals. 



The posterior spinal arteries have not been studied. 



Associated Anomalies. — In many cases the anomalous condi- 

 tions were so associated that several were present in the same case. 

 I have, therefore, introduced diagrams of a number of the most 

 interesting cases, and have described three somewhat in detail.- 



Pathological Conditions of the Arteries. — It was a matter of 

 some surprise and interest to find that no less than 148 of the 220 

 cases showed some degree of arterio-sclerosis. However, as 138 

 of the patients were over sixty years of age this may be accounted 

 for. In this connection it is well to bear in mind that arterial 

 thrombosis, one of the most common accidents of arterio-sclerosis 

 in the aged, is most apt to result seriously in these anomalous 

 states of the arteries. Bullen claims that arterial anomalies are 

 most frequent in paresis; in thirteen cases of this disease in my 

 list, six showed slight anomalous conditions, while some were nor- 

 mal in arrangement and not diseased. 



Of the cases studied seventy were of senile dementia; forty, 

 chronic dementia; fifteen, dementia precox; fifteen, epileptic 

 dementia; nineteen, chronic melancholia; fourteen, chronic mania; 

 thirteen, paresis; eight, manic depressive insanity; seven, organic 

 dementia; four, terminal dementia; three, acute mania; three, 

 imbecility; three, acute confusional insanity; two of toxic insanity; 

 two, acute melancholia; and one each of acute confusional insan- 

 ity and acute febrile delirium. It is perhaps well to state that 

 under a more modern system of classification some of the above 

 diagnoses of the mental diseases, made when the patients were 

 admitted to the hospital, would be materially changed. 



Case of Anomalous Circle of Willis. 



No. 1926. A. C; white; male; aged 78; soldier; nativity, Ohio. Mental disease, 

 senile dementia; duration uncertain. 



Autopsy partial, only the brain being examined. 



^ Sixteen of these diagrams, Figs. 3-6, are included among the descriptions of the forty cases abstracted 

 from the complete list of 220 cases. They are, however, sufficiently clear to be understood without 

 reference to the descriptive list. 



