PLATE y. 



Structure of wall of acinus, mature glands of parotids : capillaries, muscle 

 fibers, epithelial nuclei, and epithelial cells or poison sacs. Degenerating 

 forms of glands. 



Figs. 51 and 54. Vertical, tangential sections of glands. Beginning at 

 periphery of photograph. — connective tissue, network of capillaries, muscle 

 fibers, naked epithelial nuclei. Fig. 51, in addition, shows secretion and three 

 epithelial cells or poison sacs. The muscle fibers of the two glands appear 

 in different states of contraction, x -1*^- 



Fig. 52. Section horizontal to glands. Walls of two adjacent glands and 

 intervening connective tissue. Upper gland shows a cluster of epithelial 

 cells or poison sacs. Lower gland shows well the transverse view of muscle 

 fibers. X -10. 



Fig. 53. Vertical section of collapsed gland between two filled glands. 

 Note the capillary network, and the similarity of the transverse view of the 

 muscle fibers at the base, to a cubii-al epithelium, for which several writers 

 have mistaken it. X -1*^- 



Fig. 55. Vertical section of glands and cutis, showing blood-vessels in 

 lower cutis layer, with branches leading to base of glands, and capillary net- 

 work about same, x "^~*- 



Fig. 5(». Vertical section of gland at lower pole. From below upward, con- 

 nective tissue, capillary and corpuscles, matrix with imbetlded muscle fibers 

 and attached epithelial nuclei, and secretion and detached nuclei. X -1<5. 



Figs. 57 and 58. Vertical sections. In tlJe inner battery, appears part of 

 a mature, completely filletl gland, and degenerating forms, the lower one of 

 which in 57 opens to the inner side of the cutis and is filled with corpuscles. 

 In the region of the degenerating forms, occur a relatively greater number 

 of small glands, which show considerable gradation, x ■1^>- 



