APPENDIX. 535 



to the superior concave surface of the gland, and is united 

 principally to the posterior lobe, which it also resembles 

 in structure, containing very many grandular cells in its 

 parieties. 



This gland resembles a ganglion of the sympathetic in the 

 large size of its cells, and in the arrangement of its fibrous 

 constituent ; but differs from it in the irregular form of the 

 cells, and in the absence, so far as has been yet ascertained, 

 of tubular nerve fibres. 



Pineal Gland. 



Notwithstanding the interest which exists in the minds of 

 most persons in reference to this body, and which has arisen 

 in consequence of the strange physiological speculations of 

 which it has been the subject, its structure yet does not 

 appear to have been examined with that amount of care 

 which has now been bestowed upon most of the other organs 

 which enter into the constitution of the human fabric ; not, 

 however, that its organization is uninteresting or difficult to 

 be understood, for this, while it is complex and singular, yet 

 admits of easy determination. 



The chief bulk of the pineal gland is made up of innu- 

 merable minute granular cells which, when carefully ex- 

 amined in a perfectly fresh subject, are seen to be of the 

 caudate form, the rays of the cells being exceedingly delicate 

 and slender, and apt, therefore, to be entirely overlooked. 



Imbedded in this cellular matrix, and, for the most part, 

 collected in the centre of the organ, there may be noticed 

 numerous particles of stony hardness of various sizes, and 

 mostly of a rounded form, and the larger of which are plainly 

 visible to the naked eye. Of these bodies, I have never en- 

 countered any satisfactory description; they are not, as 

 generally considered, mere inorganic and earthy particles, 

 but structures of a definite and complex organization, con- 

 stituting an essential element in the composition of the pineal 

 gland. When viewed with the half or quarter inch object- 

 glass, the larger of these bear much resemblance to masses of 



