Hatai, Spinal Ganglion Cells. 35 



understand their final destination it is necessary to describe the 

 migration of the nuclear substance more in detail. Figures 4, 

 5, 6, 7 and 8 illustrate this. The granules, for the most part 

 accessory nucleoli, may be both larger and smaller than the other 

 granules contained in the nucleus. They stain deep black with 

 iron-haematoxylin and rather pinkish red with the tri-color 

 method ; that is, their staining reaction resembles very closely 

 that of the Nissl granules. These accessory nucleoli, there- 

 fore, can be distinguished from the nucleolus since the latter is 

 composed of the two substances, basophile and oxyphile. In 

 each case I noticed only one granule migrating at a time, 

 although I have seen once or twice several granules attached 

 along the external surface of the nuclear membrane on the side 

 toward the process (Fig. 3). This arrangement is very rare 

 and cannot be regarded as typical. The migration always takes 

 place towards the main protoplasmic process and in addition 

 the granule is extruded in the neighborhood of the poles of the 

 nucleus where the Nissl granules first appear. After migration 

 I was unable to see these granules at any distance from the 

 nucleus, though they were abundant near to it. From this we 

 conclude that as soon as the granules migrate from nucleus, 

 they disintegrate and their substance is mixed with the sur- 

 rounding cytoplasm. If the corpuscles which have migrated 

 out of the nucleus still continue their movement until they 

 finally come out of the cell body, as is believed by Rohde, it 

 would be possible to observe such corpuscles outside of the 

 cell body, but I have not been able to find them. Therefore 

 from at least three facts : (i) that the granule after migration 

 is always found near the nucleus ; (2) that the granule after mi- 

 gration is not found in the cytoplasm at any distance from the 

 nucleus and (3) that it is not found outside the cell body, the 

 writer concludes that these granules have been disintegrated and 

 mixed with the surrounding cytoplasm. If my hypothesis is 

 correct the migration of the accessory nucleoli is another form of 

 the extrusion of the minute granules ; a second form of the 

 nuclein formation in the nerve cell — the first or commonly rec- 



