258 Dr. K. C. Sclineider on some 



"whicli, besides the longitudinal muscle, also possess muscular 

 formations running in a transverse and perpendicular direc- 

 tion ; others, again, are entirely without the transverse 

 processes, and have a rounded termination upon the surface. 

 (Concerning the remarkable muscular formations, which 

 always lie enclosed in the protoplasm of the cell, I refer the 

 reader to my detailed paper.) The peripherally rounded 

 cells are found in the case of Forshalea chiefly upon the dorsal 

 surface. In shape they agree tolerably well with the " neuro- 

 muscular " cells described by Korotneff*, but they have an 

 e])ithelial and not deep-seated position, and are merely special 

 forms of the epithelial cells in general. Other divergent 

 forms of cells, however, occur. Thus here and there the 

 central process is entirely wanting j the cell may then become 

 very similar to a bipolar ganglion-cell, though it lies at the 

 periphery ; however, the processes also divide tolerably fre- 

 quently, and thus cells also appear which look like typical 

 ganglion-cells, and I was able to determine the subepithelial 

 position of such structures. Nevertheless, however great the 

 similarity may become, there is always something in the cell 

 which tells against the supposition of a nervous element 

 therein. In all respects the Siponophoran stem appears to be 

 in little accord with the customary views as to ganglion-cells 

 in Coelenteratcs ; this is particularly noticeable in Forshalea. 

 In this form wc find in the middle line of the dorsal side 

 quite colossal cells beneath the epithelium, which are regarded 

 by Korotneft'* as the central nervous system (an interpreta- 

 tion which is adopted by Bedotf). This follows from his 

 description, however, just as little as does the nervous nature 

 of his " neuro-muscular " cells, although I believe all the 

 same that his explanation is admissible. I incline to this 

 view, however, only because I succeeded — ditficult process 

 though it is — in satisfactorily isolating these cells, for from 

 the ligures of sections, as drawn by Korotneff, every other 

 conclusion is really more probable than his own. Never- 

 theless Korotneff's views as to what is to be termed nervous 

 are in general very far-reaching ; the presence of quite 

 irregular protojdasmic processes upon a coll causes him at 

 once to decide upon their extraordinarily sensitive nature. 

 Yet the giant cells in the stem of Forshalea possess offshoots 

 whicli in length, form, and structure really leave nothing to 

 be desired, and enable us, in all probability with justice, to 



* Korotnetr. "Zur ITistologie der Siphonopboren,'' Mittheilungen Zool. 

 Stat. Neapel, 5 Bd. 

 t Bedot, " Sur VAgalmn C/niisi, n. sp.," Recueil zool. sui.«se. T. v. 



