The finer Structure of the Nerve Cells of Invertebrates. 59 



Description of Figures. 



Plate 2. 



Fig. 1. Group of nerve cells from supra-oesophageal ganglion of 

 Arion empiricorum. Sublimate-methylen blue-eosin. Zeiss obj. A, oc. 1. 



Fig. 2. Longitudinal section of a nerve cell from the infra-oeso- 

 phageal ganglion of Arion. Sub.-metliylen blue-eosin. This and the 

 following figures, where not otherwise indicated, were drawn with the 

 aid of a Zeiss homog. immersion lens 2,0 mm, apert. 1,40, comp. oc. 4, 

 and represent, fairly accurately, the conditions met with. In this cell 

 the granules are stained blue, the ground-substance red, the cell fibrils 

 red, and the neuroglia fibrils red. 



Fig. 3. Same as Fig. 2. "Polstelle". 



Fig. 4. Longitudinal section of a nerve cell of Helix pomatia. 

 Infra-oes. gang. Sub.-methylen blue-eosin. Chromophilous granules in cell 

 body, blue; ground-substance, red; fibrils, red; coarse neuroglia fibrils, 

 red. "Polstelle". 



Fig. 5. A portion of an infra-oesophageal ganglion of Helix. Sub.- 

 safran in-light green. Zeiss obj. A, oc. 1. 



Fig. 6. Long, section of a nerve cell from the infra-oes. gang, of 

 Helix. Sub.-safranin-light green. Granules , red ; ground - substance, 

 green ; cell fibrils, green ; neuroglia fibrils, green. 



Fig. 7. Long, section of a nerve cell of Helix. Infra-oes. gang. 

 Flemming's solution-safranin-light green. Granular lines. Granules, red; 

 ground substance, green ; cell fibrils, green ; neuroglia fibrils, green. 



Fig. 8. Freshly isolated nerve cell of Limax maximus (infra-oes. 

 gang.) progressively stained in a solution of methylen blue. Structure 

 of nucleus not indicated. Granules in cell body darker than ground- 

 substance. Axis-cylinder process lighter than cell body. 



Plate 3. 



Fig. 9. Nerve cell of Helix. Long. sec. Infra-oes. gang. Sub.-pro- 

 gressive iron-haematoxylin. Shows artificial nuclear process. Detailed 

 structure of cell body omitted. 



Fig. 10. Small nerve cell of Helix (infra-oes. gang.) lying conti- 

 guous to an axis-cylinder process. Shows the contrast which exists 

 between the manner in which the axis-cylinder process and cell body 



