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the brains of two Japanese, two Papuans and "a distinguished American 

 scientist". Two very clear illustrations exhibit this "limbus" in a well- 

 developed form in one of his Japanese brains^). 



In the brains of the various people found in Egypt this structure 

 is so often present that the question has to be asked if it should not 

 be regarded as a normal appendage of the Egyptian brain. Thus in 

 36 adult Fellaheen hemispheres taken at random there was no trace 

 of the "limbus" in only 14 cases; in 11 instances it was very small 

 and in 11 hemispheres it assumed the fully-developed form represented 

 in the figures of Retzius and Spitzka. 



Moreover it is quite rare to find the limbus symmetrical in the 

 two hemispheres. In one case only (of those in which the limbus was 

 large) were the two sides symmetrical and of the other 10 the right 

 limbus was much smaller than the left in all except two cases. In 

 16 adult Soudanese (Negro) hemispheres the limbus was absent in 6 

 and was well-developed in 5 hemispheres, in two pairs of which it 

 was about equally developed on the two sides ; in the other case there 

 was a large left limbus and an insignificant right limbus. 



In 12 hemispheres of men coming from the Balkan States and 

 Syria (all of which agree in being brachycephalic and in having an 

 asymmetrical occipital region) the limbus was completely absent in 

 5 cases and very small in one. In all the brains the large limbi 

 belonged to left hemispheres. The corresponding right hemisphere of 

 one case had no trace of a limbus: in another it was very small: 

 and in the other two the limbus was very large in both hemispheres 

 and bigger on the left than the right side. 



In Retzius's case the limbus was more pronounced on the left 

 hemisphere and apparently also in three of the four cases to which 

 Spitzka specifically refers. 



So far as these scanty results enable one to judge there is a 

 most pronounced tendency for this peculiar structure to develop on 

 the left in preference to the right hemisphere. 



In its best -developed form the postorbital limbus is a crescentic 

 projection from the orbital operculum, which is flattened against the 

 antero-superior aspect of the temporal region of the brain. Its re- 

 lations are shown in the accompanying figure, which represents part 



1) Edward Anthony Spitzka, The Postorbital Limbus; a Formation 

 occasionally met with at the Base of the Human Brain. Philadelphia 

 Medical Journal, April 11th, 1903. 



