392 MONTGOMERY. [Vol. XIII. 



In none of the nemertean ganglion cells are neuroglia fibres 

 present; there seems to be no penetration of these elements 

 into the cells, and the spongioplasm of the latter is certainly 

 not produced by them. 



There remain to be described certain bodies occurring in the 

 cytoplasm of III in Z. gesserensis and L. sp., these bodies being 

 restricted to these cells in this genus and absent in all ganglion 

 cells of CerebrahLhLs {Gr. in Figs. 3, 6, 8, 9, 11, 12, 14, 15). 

 These are frequently larger than the nucleolus and of a spheri- 

 cal or oval, regular shape, and are not refractive. After the 

 use of a double stain, they stain usually with eosin, sometimes 

 with haematoxylin, but always more intensely than the surround- 

 ing cytoplasm, though seldom as deeply as the nucleolus. Struc- 

 turally they are homogeneous, with a peripheral membrane, which 

 may be scarcely discernible, or in other cases of considerable 

 thickness; this membrane always stains more intensely than 

 the enclosed portion, and forms a boundary against the sur- 

 rounding cytoplasm. These bodies do not occur in all cells, 

 but only in about one-sixth of the total number; when they are 

 present, it may be but a single one, more frequently four or 

 five, apparently never more than about fifteen. There is also 

 no regularity in their distribution, such as a concentric or radial 

 arrangement, and in the same cell they are usually of various 

 sizes and of different staining power; sometimes, however, two 

 of equal size and similar staining power lie in contact (Figs. 1 1, 

 16), so that a distribution in pairs seems to be not infrequent. 

 They are always absent in the nerve tubule. To these cyto- 

 plasmic bodies may be applied the term chromophilic corpuscles, 

 to distinguish them from the chromophilic granules in the 

 ganglion cells of other animals. These corpuscles are certainly 

 not artifacts, since they become preserved equally well with 

 Hermann's and Fleraming's fluid and with sublimate (aqueous 

 with or without acetic acid, alcoholic solutions). Further, they 

 cannot be considered parasitic organisms, since they are found 

 only in these cells in Lineus, and not in the other ganglion 

 cells nor in the surrounding neuroglia; they are also not patho- 

 logical, since I found them in all (about a dozen) of the individ- 

 uals studied. Again, they cannot be regarded as aggregates of 



