TAPE-WORMS OF THE SITC-EAMILY AVITELLININ.E. o67 



In the ganglia of the scolex nerve-cells are very prominent^ 

 their large size and deep staining (with Ehrlich's liEema- 

 toxylin) making them riiost conspicuous. Multipolar ganglion 

 cells were most frequently met with in the ganglia, bipolar 

 in the nerves. 



The multipolar ganglion cells (fig. 38) have a reticulated 

 or spongy protoplasma, which stains dark blue with the 

 haematoxylin. From the processes of the cells the neuro- 

 fibrillae can often be traced for some distance. The nuclei 

 measure 8 /< to 9 ju long by 4'5 ^t to 8^ broad; they are 

 vesicular, and contain a large nucleolus (up to 2 jli in diameter) 

 and one or two chromatin bodies. The nucleus itself is 

 much paler than the surrounding- plasma; the nucleolus 

 stains rather lighter than the chromatin. 



In the nerves arising from the scolex ganglia large bipolar 

 ganglion cells are frequent; fig. 39 represents a portion of 

 such a cell, one end not being in the plane of the section. 

 The nucleus resembles that of a multipolar ganglion cell ; the 

 cell-plasma, however, contains tigroid bodies. From each 

 end of the cell neurotibrilhe can be traced for a considerable 

 distance. The long axis of the bipolar ganglion cells always 

 lies in the direction of the nerve. 



In the suckers one also finds large multipolar ganglion 

 cells (fig. 40) ; the}" usually lie rather nearer to the delimiting 

 membrane than to the cuticula ; their processes usually unite 

 Avith those of neighbouring nerve-cells, or they are connected 

 with each other by their neurofibrilla). A connection between 

 the sucker ganglion cells and the " Sommer-Landois" cells 

 of the subcuticular muscles of the suckers can frequently be 

 made out. 



The nuclei of the sucker ganglion cells measure from (j /x 

 to 7 fx iu diameter; they are usually globular and contain a 

 large nucleolus, measuring up to 2 /./, and one or two chro- 

 matin bodies. Small glia cells are frequent along the surface 

 of the cell processes or the neurofibrilla). 



I am not aware that anyone has yet pointed out the presence 

 of ganglion cells in the suckers ; I have already mentioned 



