Io8 'Journal of Comparative Neurology and Psychology. 



We return now to a point more directly in keeping with the gen- 

 eral purpose of this paper, namely, to the form of the small cells. 

 Hatai ('oi), apparently quoting from Dogiel, says that "the 

 number of these cells from which no axon can be traced is large." 

 Hardesty ('05) agrees that "a larger portion of these extra cells 

 belong probably to the anaxonic type of neurone, latent cells 

 which have not yet developed processes." Both Hatai and 

 Hardesty had in mind only the fact that the small cells were not 

 connected with medullated fibers in the dorsal root or peripheral 

 nerve — a fact which stands uncontested — but the conclusion 

 that these cells are necessarily anaxonic is unnecessary and mis- 

 leading. I have not been able to verify the citation from Dogiel, 

 and there seems every reason to believe that instead of being nu- 

 merous such apolar cells do not occur at all in the spinal ganghon. 

 In his extremely careful study of these structures, which lead him 

 to insist on the presence of bipolar and multipolar cells, although 

 never more than two or three such were found in one ganglion, 

 Dogiel does not mention the presence of these "anaxonic neu- 

 rones." On the other hand, he describes in detail the single 

 process of the small cell as being a typical T-shaped process with 

 two branches, one directed toward the spinal cord, the other 

 toward the periphery. These processes are usually destitute of 

 myelin, but a few are medullated for a part of their course. He 

 was able to trace these non-medullated processes of the small cells 

 into the dorsal roots and mto the peripheral nerves as far as the 

 junction of the afferent and efferent fibers. 



The absence of apolar cells is again the implication of v. Len- 

 hossek in the quotation already given. "We find them (the 

 small cells) just as truly as the large cells associated with a pro- 

 cess which divides in a typical way." But v. Lenhossek does 

 not leave the question in this obscure way, but says, in another 

 place (Bau des Nervensystems, p. 268), "If we study the spinal 

 ganglion of one of the more highly developed vertebrates or even 

 the frog with suitable isolation, teasing or staining methods, we 

 find in it, in addition to the interstitial connective tissue, blood 

 vessels and nerve fibers, also numerous nerve cells of varying size 

 of which the typical form is unipolar. There are 770 apolar cells. '^ 



We have also to note the negative findings of Hodge ('89), who, 

 having obtained physiological results that lead him to expect 

 large numbers of apolar cells in the spinal ganglia of frogs, under- 



