A NOTE ON THE SIGNIFICANCE OF THE FORM 

 AND CONTENTS OF THE NUCLEUS IN THE 

 SPINAL GANGLION CELLS OF THE FOETAL 

 RAT. 



By Shinkishi Hatai. 



[From the Neurological Laboratory of The Unt~ersity of Chicago.) 

 With Plates III and IV. 



In the course of an investigation on the growth changes 

 in the nerve cells of the white rat, the writer noticed that the 

 nucleus very often had a peculiar shape ; the shape being simi- 

 lar to an amoeba exhibiting pseudopodia-like processes along 

 one side. Careful observation revealed the fact that this pecu- 

 liar form of the nucleus occurs normally during the period of the 

 early growth and in attempting to explain it we meet several 

 interesting questions of histological as well as physiological 

 importance. The results here reported form a part of a series of 

 observations on the growth changes in the developing nerve 

 cells. 



For this investigation, the intrauterine embryos of cat, 

 pig and white rat were used. The present description and 

 drawings are, however, based entirely on preparations from 

 white rat. Unless otherwise mentioned, the description 

 also applies to the cat and pig. The tissue was preserved 

 in a normal salt solution saturated with HgCl ; in Caknoy's so- 

 lution and in Graf's chrom-oxalic mixture. For the micro- 

 chemical test for P. and Fe., however, the tissue was fixed ad- 

 vantageously with 95 % alcohol. The paraffine sections were 

 made 3 to 6 micra in thickness, and were stained with Heiden- 

 hain's iron-haematoxylin alone or sometimes followed by i ^ 

 aqueous solution of eosin and Biondi-Ehrlich's tricolor stain. 

 Other sections were stained with toluidin blue and eosin. 



