104 



FREDERICK TILNEY AND LUTHER F. 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 



St. 



Pig. 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- 



