38 foumal of Comparative Neurology and Psychology. 



As supplementary to the foregoing the following observa- 

 tions may be added: (i) the pseudopodia-like processes of the 

 nucleus as well as the migration of the accessory nuclei are 

 present only at a very early stage in the development of nerve 

 cells, at the time when the Nissl granules have not yet appeared 

 or are found in very small amounts, and when the cell body 

 needs an abundant supply of formative materials. The patho- 

 logical as well as experimental studies give us still stronger evi- 

 dence for the foregoing view. 



Pathological ajid experimental evidence. — The morphological 

 completeness of the cell body is attained in an early foetal 

 period when metabolic processes in the cell body are very active 

 and we associate the formation of pseudopodia-like processes 

 and the migration of accessory nucleoli and of the minute gran- 

 ules, with the hyperactivity of the cell at this time. The ex- 

 perimental studies of the nerve cells made by a large number of 

 investigators (Hodge, '92 ; Mann, '95 ; SjcIvall, '03 ; and 

 others) show that when the nerve cell is stimulated with the 

 electric current, the nucleolus becomes first swollen and later 

 shrunken ; the outline of the nucleus becomes irregular, form- 

 ing pseudopodia like processes (Hodge, see figures) ; accessory 

 nucleoli migrate out of the nucleus (Holmgren) ; acidophile 

 substance or neurosomes are sent from the nucleus into cell 

 body (Levi) ; at the same time the Nissl granules are quickly 

 disintegrated. These observations favor my hypothesis of the 

 metabolic processes in the cell since they are similar to those 

 changes which take place normally at an early stage in the his- 

 tory of the cell body when it is actively growing. As a result of 

 the electric and other stimulation the reserve materials of the 

 Nissl granules are used up very quickly and for the mainte- 

 nance of the cell a new supply of the substance is demanded. 

 The migration of the nuclear contents and the quick absorption 

 of the necessary materials from the cell body into the nucleus 

 by means of the pseudopodia like processes are both necessary. 

 Notwithstanding that a large number of investigators have ex- 

 amined the nerve cells under various conditions, the pseudopo- 

 dia-like processes have been overlooked by most of them. 



