1028 



literature — I have not found a single mention of them in a whole 

 series of recent publications on this subject that 1 have looked 

 through. iMüLLER gives the name of "Cellkoloiiim" to these groups of 

 nerve-cells and distinguishes between regulai- and irregular colonies. 

 "Die ersteren" -- the i-egular ones — "sind nach aussen durch eine 

 cirkelrunde Kapsel vom selbigen Aussehen wie diejenige, welche 

 die grossen Zeilen umgiebt, begrenzt; innerhalb dieser Kapsel linden 

 zich zwei, drei oder vier Zeilen sehr regelinassig wie Sectoren uiu 

 einen Mittelpunkt geordnet". Muller also found bridges of piotoplasm 

 connecting the dilferent cells of the colony with each other. I have 

 not found in my preparations any colonies of cells which showed 

 this regular an-angement of their cells, resembling a sector of a 

 circle, although there are several tlgures of colonies in which the 

 cells are very nearly equal in size; but in these cases they aie 

 situated side by side, although they do not always form such long 

 rows as the one shown in fig. 4. Most of the colonies observed by 

 me are quite clearly built up of cells that are dilferent in size, and 

 it seems as if one might place them all in the group that Mült.kk 

 describes as irregular. With i-egard to the significance of these 

 colonies Muller writes: "Vielleicht steht das Vorkommen dieser 

 Bildungen mit Regenerations-phanornenen in den Spinalganglien in 

 Verbindung", but he |)oints out that, as he had lU) opportunity of 

 studying the processes of these cells, his statement on this point can 

 only be a supposition. He continues: "So viel geht jedoch aus dem 

 unbedeutenden Vorkommniss bei alteren Thieren von diesen Bildungen 

 — Koloniën und Halbnionden — welche bei Jungen Thieren' zahlreich 

 auftreten, hervor, dass sie Entwicklungsstadien von (Tanglieuzellen 

 reprasentieren und ferner, dass die Entwickelung der Spinalganglien 

 eine langsame ist, welche erst in spateren Zeitraumen von dem 

 Leben des Thieres abgeschlossen wird." 



In tearing preparations of older animals the same investigator found 

 that the crescent-shaped cells that are situated within the same 

 capsule as other ganglion cells, have no processes. These observations 

 of mine, however, are not made from tearing preparations, in which 

 one has of course always to reckon with the possibility of the 

 removal of processes that have really been present, but are 

 made from continuous series of intensely impregnated Bielschowsky- 

 preparations, in which one can very easily look for these colonies 

 section by section. In the series of sections from which fig. 4 

 is taken there is no trace of any processes. The spinal ganglion 

 in question is intensely impregnated according to the method mentioned 

 above. The impregnation is very successful ; not only the axons. 



