119 



lightly with haematoxylin, 9 /^ long by 4-5 f* wide; it contains a large, 

 round, dark nucleolus, not quite 3 i« in diameter, and up to four smaller 

 bodies, staining equally dark. 



The total length of one of the fusiform nerve-cells is 30 f', its fibril 

 can be followed on one side for further 36 i«, breadth about 9 i^. These 

 cells are evidently conducting elements. Larger, more or less rounded, 

 gangUon cells are found in the ganglia at the origin of the nerves. I can- 

 not state definitely whether they are multipolar or unipolar. In these 

 cells the tigroid bodies appear to be absent, the protoplasm staining blue 

 with haematoxylin, and presenting a spongy or reticulated appearance, 

 dark meshes enclosing a lighter ground. 



The nucleus is round, rather pale, but contains a very large dark 

 nucleolus and several (six or more) smaller dark staining bodies. One 

 such cell measured 27 i-^ in diameter, its nucleus 12 i-^, the nucleolus 3 i^. 



Large ganglion cells are also found in the body of the suckers, lying 

 between the bundles of radial fibres, usually closer to the body side than 

 to the cavity of the sucker, and often form an almost definite layer. 

 (Fig. 4.) These ganglion cells do not contain tigroid bodies ; their protoplasm 

 has the same reticulated or spongy appearance as the ganglion cells of the 

 scolex gangha. The nuclei are vesicular, their membrane very distinct, 

 their body not taking stain, their shape is round to oval. The size of one 

 of these cells measures 18 /'-' across, the nucleus 9 z-* by 6 i^-. nucleolus 3 ^. 

 Besides the nucleohis there are a few (two or three) smaller dark staining 

 chromatine bodies, often very closely approached to each other. 



These cells and the bipolar nerve-cells in the commissures described 

 above are evidently the " Myoblasts " of Pinter and Zschokke. They 

 are evidently not muscle cells ; their appearance is, if possible, even more 

 typical for nerve elements in Anoflocephala magna, Abilg., than in Stilesia, 

 owing to their larger size. (Fig. 5.) One specimen measured in Anofloce- 

 fhala magna: nucleus 12 i" long by 9 f* broad, vesicular, nucleolus distinct, 

 round, 4 /-<■ in diameter. Protoplasma staining dark with haematoxylin, 

 reticulated or spongy in appearance, distally the meshes arrange them- 

 selves more and more to parallel threads and finally lose themselves in 

 typical neurofibrills, which can be traced some distance. No cell mem- 

 brane. Total length (exclusive fibrillae) 75 /'■', breadth 15 f-; the neuro- 

 fibrillae could be traced as a definite thread for 36 i-^ on one side, 60 i-'- on 

 the other. The fibrillae of the longer side could be seen to divide at their 

 end and to connect with other similar ganglionic cells. In Anoflocephala 

 as in Stilesia, these cells are restricted more or less to a definite zone, near 

 the middle of the radial fibres, and form a definite nervous system in the 

 suckers. 



In the strobila on horizontal sections one sees occasionally nerves 

 proceeding from the lateral nerve towards the lateral margin, accompany- 

 ing the genital ducts. They are, however, hard to find, and cannot be 

 followed for any distance. 



