ORGANS OF NEURAL EXCRETION 95 



its direct bearings on the great problem of life and health. 

 In disposing of this great mass of excretory material, its 

 anciently believed, but now denied glandular texture and 

 character must simply be " what is required " to enable it 

 to deal effectually with it. Hence, we may be prepared to 

 find that the serous or fluid part of it can effect an easy 

 exit through its wall into the surrounding blood channels, 

 leaving the residual or true pituitary portion to be dealt 

 with by its proper gland textures. 



FIG. 25. TRANSVERSE VERTICAL SECTION OF THE NASAL FOSS.E SEEN 

 FROM BEHIND. (Arnold.) f. 



i, part of the frontal bone; 2, crista galli ; 3, perpendicular plate of the ethmoid; 

 between 4 and 4, the ethmoidal cells ; 5, right middle spongy bone ; 6, left lower 

 spongy bone ; 7, vomer ; 8, malar bone ; 9, maxillary sinus ; 10, its opening into 

 the middle meatus. 



This process of excretion may, therefore, be regarded 

 as a sifting and cleansing process, and the central part of 

 the scavenging economy of the cerebro-spinal lymph highways 

 and byeways. We feel constrained likewise to claim for 

 the pineal gland that it has been properly named by the 

 early exponents of anatomical learning, and that its later 

 nondescript character has been wrongly assigned to it, and 

 we claim further that it plays a part in the excretory work 

 of the third or central ventricle. 



The pineal gland occupies anatomically a very different 

 position from that of the pituitary, viz. the roof, instead 

 of the floor of the ventricular cavity, and so of necessity 



