No. 2.] WfES ON DISTOMUM PATELLARE. 



The body of the bi- or multipolar giant-cell varies from 20 //. 

 to 40 fji in diameter, the processes from 30 /* to 50 //, in length. 

 The ovoid or ellipsoidal nucleus is distinguished by its size 

 (12 /u, by 9 /u) and by its one large nucleolus from all the 

 other nuclei of the body save those of the excretory cells, 

 which it closely resembles. The cytoplasm is a fine reticulum 

 whose meshes may elongate so that it becomes fibrillar-looking; 

 usually it looks reticular around the nucleus and more fibrillar 

 toward the cell-periphery and in the processes. Fine granules 

 are scattered in the meshes of the cytoplasm and occasionally 

 a number of large, deeply staining granules occur, like those 

 found in some of the sensory papillae. 



Most of the giant-cells are found near the body wall, but they 

 also occur near the cerebral ganglia and nerve-trunks, are 

 scattered through the suckers, and very fine specimens lie 

 upon or near the extrinsic muscles of the ventral sucker. The 

 size of the cells and the winding of their processes prevented 

 me from tracing the distribution of all the processes of any one 

 cell. Processes of these cells may pass (a) into the nerve- 

 trunks or ganglia, (b) to muscle-fibers, (c} to the sensory papil- 

 lae, (d) to the body wall where they spread out as the endings of 

 the ventral nerves do, in a plexus of delicate, anastomosing fibrils. 



(d) I can confirm on this point the work of Monticelli and 

 Schuberg. 



(b) Many of the giant-cells are connected by at least one of 

 their processes with a muscle. Most of the processes of the 

 multipolar cells lying near the base of the ventral sucker were 

 traced to its extrinsic muscles; but, contrary to what Blochmann 

 and Bettendorff found, fibers belonging to different anastomos- 

 ing systems may be supplied with processes from the same 

 giant-cell. This indicates that these cells are not myoblasts. 

 The processes passing to the muscles break up into varicose 

 anastomosing fibrils which can be traced for some distance 

 along the surface of the muscle, developing here and there 

 delicate thickened endings which are closely opposed to the 

 muscle fibrils (Fig. 3). 



(c) The fibrils of a process passing to a sensory papilla con- 

 verge until they apparently fuse to form the fibril entering its 



