122 THE NERVOUS TISSUES 



association neurones within the ganglion. Nerve fibres from the 

 sympathetic ganglia also enter the spinal ganglia and form peri- 

 cellular arborizations about the cells of the second type. Dogiel 

 also finds that multipolar ganglion cells occur in the spinal gan- 

 glia of the adult as well as of the embryo. 



In the sympathetic ganglia Dogiel * likewise recognizes two 

 cell types : (1) small multipolar fusiform or stellate nerve cells 

 with 5 to 20 dendrites and a neuraxis which enters the nerve 

 trunks as a non-medullated fibre, but may later acquire a thin med- 

 ullary sheath ; (2) larger spheroidal nerve cells with 1 to 16 den- 

 drites and a single neuraxis which also enters the nerve trunk as 

 a non-medullated nerve fibre, but may later acquire a very thin 

 medullary sheath. The dendrites of Type II are distinguished 

 from those of Type I by being very long and slender and also by 

 entering the nerve trunks, to pass, presumably, to neighboring 

 ganglia. The dendrites of the first cell type, on the other hand, 

 are shorter, thicker, and end in relation with other cells within 

 the same ganglion. 



The ganglionic cell group is eccentrically placed as regards the 

 axis of the nerve trunk, some funiculi apparently passing the 

 ganglion without being in any way connected with its nerve cells. 



The sympathetic differ from the cerebro-spinal ganglia chiefly 

 in the preponderance of non-medullated nerve fibres in the former 

 and of the medullated type in the latter. Just as the cerebro- 

 spinal ganglia receive a few non-medullated sympathetic fibres, so 

 also the sympathetic ganglia receive, through the medium of the 

 rami communicantes, a certain number of medullated nerve fibres 

 from the cerebro-spinal system. Moreover, with the intense stain- 

 ing method of Weigert very thin medullary sheaths may now be 

 demonstrated where formerly they were not suspected. 



The ganglia are supplied with blood vessels and lymphatic 

 vessels in a manner similar to the nerve trunks in whose course 

 they occur. 



*Anat. Anz., 1896. 



