GANGLION CELLS IN THE SPINAL CORD. 297 



nervous system, and therefore especially between the 

 cells of the sympathetic and those of the brain and spinal 

 marrow. But in this point also the contrary has proved 

 to be the case, especially since Jacubowitsch has brought 

 to our knowledge the new fact, of the correctness of 

 which I have fully convinced myself, namely, that struc- 

 tures which are perfectly analogous to the ordinary gan- 

 glion-cells of the sympathetic, also occur in the middle 

 of the spinal marrow and several parts which are consi- 

 dered to belong to the brain. It may therefore be said, 

 that cells belonging to the sympathetic nerve, concerning 

 which it has already long been known that a great part 

 of its fibres have their origin in the spinal marrow, are 

 really also met with in the spinal marrow, and that in this 

 respect also the cord does not form a simple and neces- 

 sary contrast to the main trunk of the sympathetic. 



If we examine the spinal marrow, which affords the 

 clearest representation of the plan of a true nervous cen- 

 tre in the narrowest meaning of the word, a little more 

 closely, we everywhere find in its grey substance (the 

 horns), and indeed in nearly every transverse section, 

 different kinds of ganglion-cells. Jacubowitsch has, and 

 I believe him to be in the main correct, distinguished 

 three different forms, of which he calls the one motor, 

 the second sensitive, and the third sympathetic. These 

 lie generally in separate groups. 



I shall revert to this subject when I come to speak 

 more at length concerning the spinal marrow ; here I 

 only wish to speak about the different forms of ganglion- 

 cells. The so-called unipolar forms, are, in proportion 

 as the examinations are conducted with more care, con- 

 tinually becoming more and more rare. In the great 

 nervous centres most of the cells possess at least two pro- 

 cesses, and very many are multipolar or, more accurately, 



