1889-90. J MORPHOLOGY AND PHYSIOLOGY OF THE CELL. 273 



capacity for absorbing staining reagents is increased. Later several of such 

 bent fibrillae approach one another and acquire the shape of a sickle, semi- 

 circle, or circle. The latter show all possible stages of transformation into 

 the laminated bodies and spherules, which possess a very irregular fibrilla- 

 tion appearing to consist of loose threads, while they may at times resemble 

 laminated colloid bodies. The pseudo-nuclei disappear during hunger, 

 while becoming gradually paler and less easily stainable. As to the 

 process and manner of disintegration Eberth could offer no explanation. 

 He compares these bodies with structures described by Czermak as 

 occurring in the ethmoid cartilage of the calf, and with those found by 

 Solger in the cartilage cells of the shoulder-girdle of the pike. Eberth 

 believes these structures' to be normal, and' in a sense, comparable to the 

 nodules of the nuclear network. 



Eberth states that the employment of corrosive sublimate as a harden- 

 ing reagent and of paraffin for imbedding produces contraction and 

 shrinkage in these objects, and that then one obtains the peculiar shapes 

 which possess a certain resemblance to Cytozoa. He accordingly recom- 

 mends Rabl's Fluid or Flemming's Fluid for hardening and celloidin for 

 imbedding. 



Now I have carefully gone over the whole of my preparations since 

 last October, and have during this winter made a number of new prepara- 

 tions from Diejnyctyli and young Aniblystoiiiata, using for this purpose 

 each of the three hardening reagents mentioned, frequently on pieces of 

 the pancreas from the small animal. I have found that Rabl's Fluid 

 often gives the appearance of coarse, parallel fibrillation in the pancreatic 

 cells, when neither Flemming's Fluid nor corrosive sublimate demon- 

 strated the presence of a single nebenkern in the parts of the pancreas 

 hardened with either of these reagents. Such a parallel arrangement of 

 coarse fibrillae is probably artificially produced. It appears also to cause 

 a swelling of the cytoplasmic fibrillae, whereby these are rendered more 

 distinct, and I think that to this property is due the advantage obtained 

 by the employment of Rabl's Fluid in demonstrating the elements of the 

 achromatic spindles in dividing nuclei. 



My later observations strongly confirm my view that the nebenkerne 

 are parasitic elements. In eight Ainblystomata, killed during January 

 and February, there were nebenkerne in only one, and here very abun- 

 dantly. There could be no doubt about the sharply outlined form, as 

 Steinhaus has figured it, often homogeneous but as often fibrillated. I 

 have seen quite distinctly the thickened portion of the organism which 

 simulates a head. As the Ainblystomata kept in the laboratory tank were 



