104 



FREDERICK TILNEY AND LUTHER P. WARREN 



actual ganglionic cells is doubtful. Some cells observed by 

 Hill 180 in 1894 have very long processes. Studnicka 386 observed 

 that whatever the character of the cells of the end-vesicle may 

 be, whether special sensory or not, the entire organ is not a 

 gland. By this he does not deny the possibility that the struc- 

 ture may be in part glandular. Galeotti 140 in 1896 found some 



Epid 



Cor 



Fig. 54 The epiphyseal complex in Anguilla fluviatilis, according to Leydig, 

 1896. 



V., velum transversum; Ds., dorsal sac; Po., pineal organ; St., stalk. 



evidence of secretory activity in the cells of the pineal organ in 

 these forms. In Leuciscus, he observed nuclei which had fuch- 

 sinophile granules and also nucleoli which later appeared in the 

 protoplasm. The product of this secretion was, in his opinion, 

 delivered to the lumen of the end-vesicle which is completely 

 surrounded by blood vessels. The stalk, when definitely pres- 



