THE PINEAL BODY 



101 



Johnston 194 found a number of nerve fibers constituting a layer 

 which extends from the proximal portion to the commissura 

 habenularis, where it apparently undergoes decussation form- 

 ing the so-called decussatio epiphysis. These observations were 

 made by means of the Golgi method. Other fibers end freely 

 between the cells of the stalk. These cells, Johnston thinks, are 

 rudimentary or degenerated nuclei, perhaps related to the pineal 



a 



Fig. 53 Histological structure of the wall of the pineal organ in Acipenser 

 sturio, according to Studnicka. 1893. 



eye. He found a third type of fibers in a decussation which 

 comes into relation with the ganglia habenulae. Herrick 177 in 

 1891 also mentioned such fibers in Acipenser. The proximal 

 portion consists, in the main, of small neuroglia elements with 

 some nerve fibers running in it, as already described. Stud- 

 nicka 386 does not think that there is any indication of a glandular 

 activity in this part of the pineal organ which is in any way 

 comparable to that of the proximal portion in the pineal organ 

 of selachians. 



