450 



THE PINEAL ORGAN 



15 mm. There was no definite capsule, the growth being limited by the tissues 

 with which it came into contact. Thus it was covered laterally by vascular 



Fig. 301. — Photograph of Case i, showing Bulging through a Sub-tentorial 



Decompression. 



pia mater, and where it was invading nerve-tissue this was pushed aside and 

 compressed, the original covering having been either partially or completely 

 destroyed. The aqueductus cerebri had been flattened by pressure, its roof 



Fig. 302. — Case i. Brain after Removal, show Position of Pineal Tumour. 



being almost in contact with the floor except in the centre, where in the position 

 of the median groove in its floor the section showed a triangular space with the 

 apex directed downwards. The single layer of cubical epithelium which lines 



