128 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



positions bare, of course, led to the development of the 

 tumour in the part of the orbit behind them. The 

 internal and external recti are shown in the figure : they 

 are longer than in the normal condition, are attenuated, 

 and ilattened out into sheet-like structures. The superior 

 and inferior recti are not represented in the figure, being 



Rectus 

 Interior 



Ob liquys 

 [nrer/on 



Opfic 

 __chiasma 



FronTCLi 



R.OpficNeTve 

 '^L.Of^fic Nerve ' 

 -frontal 



liiddf'ii by the mass of the tnmoui'. All the eye muscles 

 lie on ilie surlace of the tumour, and do not pass inlo 

 its substance at any place. 



The optic cliiasma is normal, and Ihc right o])tic 

 nerve bends shaiply upwaids ;is it leaves tlic brain ca\ity, 

 and runs along tlie })()sterior surface of tlu> tumour. It 

 really lies directly underneath tlie rectus extcruus, but 



