THE FULLY DEVELOPED HUMAN PINEAL ORGAN 395 



of a Plasmodium or spongioplasm within which the nuclei of the cell- 

 elements are imbedded. In many of the spaces of the network branched 

 parenchyma cells containing pale vesicular nuclei are present. The 

 processes of these cells appear to be : 



(1) Continuous with processes of similar adjacent cells. 



(2) Continuous with the matrix of the general neurospongium. 



(3) Spread out on the perivascular sheaths of the vessels contained 



in the trabecular or fibrous capsule. 



S.D.N. 







*pv - 



CT.C. 



Pa.C. 



Fig. 265. — Section of an Adult Pineal Gland stained by van Gieson's 

 Method and Eosin, showing the Apparent Continuity of the Reticulum 

 in which the Parenchyma Cells are embedded ; and also the Relation 

 of the Parenchyma Cells to the Spaces of the Reticulum and the 

 Supporting Tissue or Neurospongium. An Interlobular Septum 

 showing Capillary Blood Vessels and Nuclei of Fibrous Connective 

 Tissue crosses the Upper Part of the Drawing obliquely. (R. J. G.) 



Cp. : capillary vessel. 



CT.C. : connective tissue cells. 



Pa. C. : parenchyma cell. 



S.D.N. : small darkly stained nucleus. 

 Sp. : space. 



The cells with the pale vesicular nuclei belong to the fully developed 

 type of pineal or parenchymal cell ; many of the parenchyma cells, 

 however, are embedded in the spongioplasm, and in this situation the 

 nucleus is usually smaller and more deeply and uniformly stained than 

 those of the cells just described. Between these two extreme types, in 

 young as well as in adult specimens, there are numerous intermediate 

 forms (Fig. 265), both with respect to the type of the nucleus and the 



