PLATE VII. 



Structure of the neck and collar of the mature gland of the parotid. 



Figs. 69-75. Transverse section of the outlet and acinus of the same 

 gland at different levels, the outlet similar in shape to that of the mature 

 gland in Fig. 25, PI. III. X 210. 



Fig. 69. View of neck, third section from surface (sections 10 microns). 

 a. — neck of small gland. 



Fig. 70. View of neck, seventh section from surface. 



Fig. 71. View of neck, ninth section from surface. 



Fig. 72. View of cog-wheel-like structure, twelfth section from surface. 



Fig. 73. View of collar, seventeenth section from surface. 



Fig. 74. View of collar, twenty-second section from surface. 



Fig. 75. View of acinus (upper gland). 



Fig. 76. Oblique section of collar, showing surrounding network of elastic 

 fibers. X 210. 



Fig. 77. Oblique section of collar of mature gland, showing two secreting 

 cells. Note thin homogeneous stratum at lower border of epidermis, x 45. 



Fig. 78. Outlet of mature gland (same as in Fig. 42). Note the separa- 

 tion of the neck from the lower half of the epidermis. X 210. 



Fig. 79. Outlet of mature gland of late fall toad (Fig. 9), showing the 

 two concentric zones of cells. X 210. 



