I ^6 /ounial of Comparative Neurology and Psychology. 



protoplasm, that they are the conducting element and are therefore 

 the seat of katabolic processes, while the protoplasm and nucleus are 

 the seat of the anabolic process. How the fibrillae are repaired by 

 the protoplasm, Pugnat says, we are absolutely ignorant. Through 

 this theory of derived substance Pugnat attempts to bring the neurone 

 theory into harmony with the results of Apathy and Bethe and their 

 followers. He thinks that whether the fibrillae as derived products 

 of the cell are continuous or not from cell to cell, the nerve cell itself 

 may be considered as an anatomically distinct unit. He would, in 

 other words, place the neurofibrillae in the same category with the 

 fibrillae of the muscle or connective tissue cell. However, before such 

 a compromise of the neurone theory is conceded Hatai's methods, by 

 which he has received such brilliant pictures of the finer structures of 

 the nerve cells and of the axone terminals, must be given a thorough 

 test. The results which he has recently published are remarkably 

 convincing. 



In the afferent neurones of the electric lobe of Torpedo Hatai 

 ('oi) demonstrates fine fibrillae in enormous numbers, crowding the 

 cell processes and the perikaryon. By serial sections through one of 

 these large cells he shows the behavior of the fibrillae within the cell 

 body. Upon emerging from the process into the cell body they di- 

 verge in clusters. Some sweep around the nucleus to form here a 

 dense net, others pass to various processes of the cell in such a man- 

 ner that there is direct fibrillar connection established between each 

 dendrite and every other deixirite and between the axone and all the 

 dendrites. By this coursing of the fibrillae from the dendrites into the 

 axone there is a beautiful spiral configuration given to the ground sub- 

 stance of the cone of origin. Superficially Hatai's figures in this case 

 have a striking resemblance to the familiar drawing of the fibrillar 

 elements in the nerve cell by Max Shultze. 



Hatai, however, makes an important step in advance by demon- 

 strating that these same fibrillae in the electric neurones of Torpedo 

 can be resolved into rows of neurosomes. Furthermore, he asserts 

 that these neurosomic fibrils in reality are a modified reticulum. It is 

 only in thicker sections and under lower magnification that the struct- 

 ure gives the fibrillar appearance. 



Hatai has demonstrated the reticular structure more exhaustive- 

 ly in the nerve cells of the white rat. He has studied these cells ('03) 

 by the methods of Bethe and Dogiel, but finds no such fibrillar 

 structures as they describe. On the other hand, he demonstrates by 

 other methods a neurosomic reticulum which is modified iutoapseudo- 



