OF SPHERICAL, OVAL, AND PTEIFORM XERYE CELLS. 193 



version into fibre, which process continues during the 

 life of the cell. It seems as if the cell revolved, and 

 at the same time had spun ofi' fibres from its peripheral 

 parts. In many cases the fibre seems to unwind itself 

 from the outer part of the cell, and in this situation 

 the gradual multiplication of the oval masses of bio- 

 plasm which are ultimately seen in the unwound fibre 

 may be demonstrated, and the youngest may be seen 

 growing in the substance of the cell itself, near the 

 surface. 



In man and the higher vertebrata the cells of this 

 class are found in all the ganglia of the so-called Sj/m- 

 jxdhetic, and in the ganglia on the posterior roots of the 

 nerves, the Gasserian ganglion, &c., which belong to 

 the same division. They are nearly spherical, and are 

 usually represented as spherical cells or globules lying 

 amongst the fibres of the gangHon. Even to this day 

 these cells are stated in many text-books to be in- 

 vested with a capsule of connective tissue, sometimes 

 as thick as the cell is wide, in which numerous nuclei 

 are represented. These are supposed to "have no con- 

 nexion whatever w^ith the nerve-fibres passing near 

 them. Nothing could be more unmeaning than many 

 of the statements made concerning the structure of 

 the sympathetic ganglion cells. Nevertheless, they 

 are repeated again and again, and the old drawings 

 of thirty years ago are adduced in support of doc- 

 trines which are utterly untenable. 



Some writers still insist upon the existence of 

 " apolar " and "unipolar" nerve-cells in many parts 

 of the nervous system, although the i*esults of obser- 

 vation positively prove the existence of two fibres in 

 the case of cells which had been previously regarded 

 as unipolar and apolar. From the cells of the sym- 

 pathetic ganglia of man and vertebrata several fii)res 

 proceed, and pass in difPerent directions soon after 

 they leave the cell. Bundles consisting of fibres 

 ffom many different cells leave the ganglion from 







