76 S. WALTER RANSON 



felt. It should be remembered that in the opinion of the writer 

 their true significance lies in their being the cells of origin of the 

 non-medullated fibers of the spinal nerves. The small cells 

 differ histologically from the large cells in being small, angular, 

 possessing a relatively small amount of cytoplasm, and in stain- 

 ing more intensely with the diffuse protoplasmic dyes (v. Len- 

 hossek '86 and '95, Fleming '95, Cox '98, Hatai '00). Ranson 

 ('08) has shown that when the spinal ganglion is stained by a 

 modification of Doaggio's 'Method vii' the large and small cells 

 present a very striking contrast; the cytoplasm of the large cells 

 is colorless except for a network of blue threads while the cyto- 

 plasm of small cells is a deep violet and almost free from such 

 threads. There are transitional cells of medium size presenting 

 some of the characteristics of both types. 



That there is also some physiological distinction between the 

 two types is indicated by the experiments of Hodge ('89). He 

 noted that after electrical stimulation of a nerve it is chiefly the 

 large cells which show the effect of fatigue, the small cells for the 

 most part being unaltered. 



Various theories have been advanced to account for the pres- 

 ence of the small cells. Rawitz ('80) considered them young 

 developing ganglion cells, the immediate result of a supposed — 

 but confessedly undemonstrated — cell division. Since mitosis 

 occurs rarely if at all in the spinal ganglia during extra uterine 

 life this theory is not tenable. Biihler ('98) believed that the 

 small cells served as a reserve and that when a large cell degen- 

 erated a small one increased in size and took its place. Hatai 

 ('02) has shown that this view cannot be held since the total num- 

 ber of cells remains constant from birth to maturity. 



Hatai ('02) has also shown that during the growing period of 

 the animal the small cells are constantly being transformed into 

 large ones. He concludes that they are ''in a growing state or 

 in a more or less permanently immature condition." After hav- 

 ing made these valuable observations he assumes without ade- 

 quate evidence that many of these small cells have no axon and 

 are by inference functionless. Hardesty ('05) agrees in con- 

 sidering them 'anaxonic' or "latent cells which have not j^et 

 developed processes." Contrary to this assumption we have 



