358 THE NERVOUS CYTOLOGY OF PERIPLANETA ORIENTALIS. 



Fig. 34. Graded formalin preparation (polychrome stain). X1800. 



Fig. 35. Diffused alcohol preparation (polychrome stain). XlOOO. 



Fig. 36. Part of the cytoplasm of the preparation from which Figure 35 was drawn. X4000. 



Fig. 37. Diffused alcohol preparation (polychrome stain). XlSOO. 



Fig. 38. Graded formalin preparation (polychrome stain). Post-mortem material. XlOOO. 



Fig. 39. Part of the cytoplasm of the preparation from which Figure 38 was drawn. X4000. 



PLATE XXVIII. 



Figs. 40, 41. Picroformalin preparation (polychrome stain). Post-mortem material. XlOOO. 



Figs. 42, 44. Graded formalin preparation (polychrome stain). Normal material sectioned and then soaked in 

 4% sodic hydrate for four hours. XlOOO. 



Figs. 43, 45. Parts of the cytoplasm of the cells from which Figures 42 and 44 respectively were drawn. X4000. 



Fig. 46. Graded formalin preparation (polychrome stain). Cell from a roach subjected to prolonged Faradiza- 

 tion. XlOOO. 



Fig. 47. Part of the cytoplasm of the cell shown in Figure 46. X4000. 



Figs. 48, 49. Picroformalin preparations (polychrome stain). Cells of roaches poisoned by Paris green. XlOOO. 



Fig. 50. Diagrammatic camera sketch of a group of cells fixed in the vapor of formalin. X345. 



Fig. 51. Diagrammatic camera sketch of a group of cells fixed in graded formalin, showing the distention of the tissue 

 and the stretching of the cells. X345. 



Fig. 52. Diagrammatic camera sketch after diffused alcohol fixation, showing a fraying of the cell edges similar in 

 appearance to that shown in Figure 51, but apparently due to the shrinkage of the cells rather than 

 to the swelling of the spaces. X345. 



Fig. 53. Diagrammatic camera sketch after picroformalin fixation, showing perinuclear condensation. X345. 



Fig. 54. Diagrammatic camera sketch after absolute alcohol fixation, showing laceration of the nuclear membrane 

 in addition to extreme perinuclear condensation. X345. 



