THE PINEAL BODY 



153 



the acini. Studnicka 391 regarded these cells as ependymal in 

 type just as in the lower vertebrates, but found no sensory cells. 

 In addition to the ependymal elements there were neuroglia 

 cells, and Studnicka in Meleagris also observed some very large 

 cells with clear cytoplasm scattered among the other groups. 

 There may be ganglionic cells, as in Acipenser. No nerve fibers 

 were observed. The epiphysis contains many isolated cells and 

 a secretion derived apparently from the ependymal cells. No 

 pigment was observed. 



Fig. 76 Section of the pineal body of Meleagris gallopavo, showing follicles, 

 according to Studnicka, 1896. 



The stalk of the epiphysis, which is of course in no sense 

 homologous with the stalk of the pineal organ, being a secondary 

 character of the epiphysis, is usually short and contains the 

 recessus pinealis. In some instances, however, it is solid. No 

 nerve fibers have been observed in it, so that the organ has no 

 neural connection with the brain. The epiphysis, including its 

 stalk or peduncle, is enclosed within a sheath of pia mater and 

 arachnoid. 



