CENTRAL ORGANS OF NERVOUS SYSTEM. 217 



is not determined with certainty ; neither is that of sympa- 

 thetic bipolar ganglion cells. We are only familiar here with 

 the unipolar cells with the descending, narrow, sympathetic 

 nerve fibres. 



We know next to nothing, at present, about the similar 

 nerve ganglia of the mammalial animal. 



Let us now pass to the sympathetic in the sense of the 

 older anatomy. In the frog we can, at least, demonstrate 

 unipolar ganglion cells. Others give us the impression of 

 the apolar, whether rightly or not we leave undecided. 



Sixteen years ago, by the aid of Remak's investigations, I 

 drew the diagramatic figure 185, as a sympathetic ganglion. 

 I repeat the figure here ; not because I regard it as complete 

 (I am far removed from this), but because I am unable to 

 present any better substitute in a more reliable manner. So 

 slight has been the advance made during this long epoch ! 

 Remak, that excellent observer, here met with multipolar 

 ganglion cells. He attributed to them 3 to 12 processes, 

 which might be increased two or threefold by further ramifi- 

 cations. They are said to at last become nerve tubes. Ac- 

 cording to what we have learned above (Fig. 176) concerning 

 the protoplasma and axis-cylinder processes of the ganglion 

 cells, this cannot very well be correct. Repeated, more accu- 

 rate investigations appear, in consequence, to be urgently 

 necessary ; but who will make them ? 



With the larger sympathetic ganglia are associated a num- 

 ber of smaller and smallest ones. This is the case in the 

 ciliary muscle and in the choroid of the eye, in the expan- 

 sions of the glosso-pharyngeal nerve passing to the oesopha- 

 gus, in the lingual branches of the ramus lingualis of the 

 fifth nerve. We also meet with similar small ganglionic en- 

 largements in the walls of the larynx, and of the bronchi, 

 in the interior of the lungs, and in the heart muscles. 



In the walls of the digestive apparatus there is a developed 

 plexus of ganglia belonging, in the first place, to the sub- 

 mucous tissue ; then there occurs in the muscles, between 



the longitudinal and annular layers of fibres, the plexus my- 

 10 



