PLATE 4 
EXPLANATION OF FIGURES 
20 Median longitudinal section of a discharging granular gland from the 
dorsal region of the tail. Granular secretion and many nuclei expelled, muscle 
layer prominent, epidermis deformed by the contraction of the gland wall. 
Zenker; Ehrlich’s haematoxylin and van Gieson. X 178. 
21 Tangential section of an emptied granular gland, showing the transverse 
markings on the outer surface of the contracted muscle fibers. Kleinenberg; 
Ehrlich’s haematoxylin and eosin. X 340. 
22 An early stage in the regeneration of an emptied granular gland. The sec- 
tion is not quite perpendicular, but passes somewhat obliquely through the lower 
end of the duct. Muscle layer intact, numerous leucocytes and pigmented wan- 
dering cells in the lumen, new epithelium developing from the intercalary region. 
Gilson; Ehrlich’s haematoxylin and eosin. X 267. 
23 Median longitudinal section of a regenerating granular gland. Somewhat 
later stage than figure 22. Old muscle layer prominent; epithelium definitely 
arranged and typically granular. Epidermal cells along the duct amoeboid. 
Kleinenberg; Ehrlich’s haematoxylin and van Gieson. X 267. 
24 Later stage of a developing granular gland, from the dorsal surface of the 
body, seen in median longitudinal section. Cells large and filled with secretion. 
Cell limits distinct, but the lumen obliterated. Within one cell the secreting 
granules are disintegrated. Neither muscles, intercalary region nor duct de- 
veloped. Kleinenberg; Ehrlich’s haematoxylin and eosin. X 178. 
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