PLATE 5 
EXPLANATION OF FIGURES 
25 Early stage in the development of a mucous gland seen in median longi- 
tudinal section. Lumen present, cluster of cells at the region of connection with 
the epidermis. JXleinenberg; Ehrlich’s haematoxylin and eosin. X 340. 
26 Later stage in the development of a mucous gland. Cubical cells arranged 
in a single layer about the lumen. Two flattened cells are shown just external 
to the definitely arranged epithelium. Duct partially formed. Kleinenberg; 
thionin and eosin. X 178. 
27 Mucous gland in which the cells are actively secreting. Cells are seen 
migrating downward from the epidermis. No duct yet developed. 23 per cent 
formaldehyde; thionin and eosin. X 340. 
28 Median longitudinal section of a mucous gland from the ventral surface 
of the body. Duct fully developed; cells very large and filled with secretion; 
nuclei small, irregular and densely stained. Near the duct some of the gland 
cells are ruptured. 23 per cent formaldehyde; thionin. X 178. 
29 Later stage in the regeneration of a granular gland. Note the wide duct, 
mitosis, absence of a definite intercalary region, and the pigmented wandering 
cell between cells of the gland epithelium. Secreting begun by the new epithe- 
lum. Clear club-like masses on the ends of the younger cells extend into the 
lumen. Kleinenberg; Ehrlich’s haematoxylin and eosin. X 267. 
30 Portion of wall from a longitudinal section of a granular gland, showing 
the entry of free nerve fibers between the muscle cells.- Ranson’smethod. X 405. 
31 Tangential section of the wall of a granular gland, showing nerve endings 
on muscles. Ranson’s pyridin-silver nitrate-pyrogallic acid. XX 405. 
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