Mayer. — Wing Scales. 
PLATE 6. 
All of the Figures are from Danais plexippus, and the specimens were stained 
with Kleinenberg’s hematoxylin, followed by safranin. 
Fig. 31. View looking down upon the upper (i.e. exposed) surface of one of the 
large scales situated upon the nervures. Stage about four days before 
emergence. 
Fig. 32. Cross section of scale like that of Figure 31. Exposed surface below in 
the figure. 
Fig. 53. Leucocyte found within the scale represented in Figure 31, about four 
days before emergence. 
Fig. 34. View of upper surface of one of the smaller scales, such as are found 
between the nervures. Drawn about four days before emergence. 
Fig. 35. Cross section of scale like that of Figure 54. Exposed surface below in 
the figure. 
Fig. 56. Longitudinal section of a scale in the “transparent stage,” about eight 
days before emergence (compare Figure 9). 
Fig. 37. Longitudinal section of scale in the “ white stage,” about five days before 
emergence. 
Fig. 58. Longitudinal section of scale after the withdrawal of the protoplasm, 
about four days before emergence. 
Figs. 39-43. Longitudinal sections of scales, showing successive stages in the 
degeneration of the leucocyte that enters the scale. 
Fig. 44. Scale just before emergence, showing disposition of the pigment repre- 
sented in black. 
Fig. 45. Pupal fore wing, natural size. 
Fig. 46. Imaginal fore wing, natural size. 
Figs. 47-52. Free leucocytes found in the lumen of the wings. 
