63 



Total 1619 cases 

 When we also take into consideration the numerous examples which 

 every anatomist sees daily in the dissecting room of normal cerebral 

 arteries it is obvious that the particular variation with which this 

 paper deals is one of the rarest of anatomical variations, and that 

 the present example is the second on record, Batujeff's being the 

 first. 



One other highly interesting and important observation remains 

 to be made and that is that the brains of criminals and congenital 

 lunatics have apparently a much greater percentage of arterial variations 

 at the base of the brain, with or without a diminished calibre of the 

 blood vessels concerned, than is apparently the case in more healthily 

 minded persons, 



Blackburn (15) examined the blood vessels at the base of the 

 brain in 220 lunatics and found abnormalities present in 155 cases. 

 He also found abnormal narrowness of the a. vertebralis, on the 

 right side 21 times, on the left side 12 times, and on both sides 

 twice. 



Barbiert, quoted by Longo (26) examined 145 cases of idiots 

 and found anomalies in 15 ^/q. Lombroso, quoted by the same author, 

 found 26 anomalies in the brains of 71 criminals. Giacomini has 

 also noted the abnormal size of the aa. communicantes in criminals. 

 Frigerio noted 21 vascular abnormalities out of 37 cases of insane. 



Mori's work (30) brings out the point even more strikingly. Out 

 of 35 cases from the insane he found no less than 32 with arterial 

 anomalies, whilst in a corresponding number from the sane there were 

 only 13 arterial anomalies. 



Parnisetti (31) found in the brains of criminals vascular ab- 

 normalities in no less than 65—51 %. 



We have been so struck with these observations on the part of 

 the Italian school of anatomists that we have arranged for a member 

 of the staff of this department — Dr. Gordon Shaw — to make a 

 systematic series of observations of the brains of congenitally insane 

 persons together with a check series of observations on the brains of 

 a corresponding number of sane persons, and he is now engaged in 



