526 Proceedinfjs of the Royal Irish Academy. 



Cunningham finds to be as follows : — Length, 38 mm. ; depth, 28 mm. ; 

 breadth, indefinite, oTving to obliteration of the normal lateral 

 boundaries. Concerning the right sphenoidal fissures he says : — 

 " Looking into the orbital cavities of ]ilagrath's skull it is seen that 

 the right sphenoidal fissure has undergone a great expansion. This is 

 more marked in its inner wider part. Here it is no less than 11-5 mm. 

 in width, and at least twice as wide as the corresponding part of th.e 

 left sphenoidal fissure." 



I have myself examined Hagrath's skull, and I can confirm the 

 above quoted description in all respects. 



There can, I believe, be no reasonable doubt but that the destruc- 

 tion of the olivary eminence here involved the destruction of the optic 

 commissure, which lies on it ; and that the least visual defect we can 

 assign to !Magrath is the usual one of acromegaly — bi-temporal 

 hemianopsia. The existence of this defect in a person of a low order 

 of intelligence, such, as ICagrath is stated to have been, and of no 

 education as he probably was, is quite compatible with the absence of 

 any statement as to defective eyesight in the accounts of him that we 

 have ; for in this, as in other forms of hemianopsia, the fixation point 

 often escapes completely, owing to overlapping of its supply from each, 

 cerebral visual centre ; and hence, for objects looked at straight in 

 front, no great difiiculty of sight may have been experienced. Objects 

 lying to the left-hand side could be observed with the seeing half of 

 the right retina, while objects lying to the right-hand side could be 

 observed with the seeing half of the left retiaa, in so far as the bridge 

 of the nose did not interfere. If then bi-temporal hemianopsia was 

 the only visual defect in Magrath's case, the vision he retained may 

 very well have been sufficient for his limited requirements, and he 

 may even have been so little inconvenienced as to have been himself 

 unaware that there was anything wrong with his sight. 



But, I think, without carrying conjecture too far, we may conclude 

 that, for some time before his death, Magrath had other, and more 

 serious, loss of sight. From the appearances in the skull it is obvious 

 that the growth of the hypertrophied pituitary body was especially 

 marked towards the right side, and that it must have involved the 

 right optic tract containing, with others, the fibres for the supply of 

 the outer half of the right retina. This would result in loss of function 

 of the outer half of the right retina, and blindness of the nasal side of the 

 right field of vision ; or — as we have shown that the temporal side of the 

 field must have been lost from pressure on the commissure — complete 

 blindness of the right eye. If this were so, the giant can only have 



