408 



CHANGES IN ALBUMINOUS CELLS. [BOOK 11. 



of the granules, when these are visible, being naturally earliest and 

 most marked at the outer portions of each cell, and progressing 

 inwards towards the lumen, the whole cell becoming smaller and 

 as it were shrunken. 



In the cells of the parotid gland and other albuminous cells the 

 granules seen in the living or fresh cell differ from the granules 

 seen in the pancreatic cell, inasmuch as they are easily dissolved or 

 broken up by the action of alcohol, chromic acid, and the other 

 usual hardening reagents, and hence in hardened specimens have 

 disappeared. In consequence, in sections of hardened and pre- 

 pared albuminous glands the difference between resting or loaded 

 and active or discharged cells may appear not very conspicuous ; 

 and this is especially the case in the parotid gland of the rabbit 

 when the activity has been called into play by stimulation of the 

 auriculo-temporal nerve. When however, either in the rabbit 

 or the dog, the cervical sympathetic is stimulated, though the 

 stimulation gives rise in the rabbit to little secretion of saliva, 

 and in the dog to none at all, a marked effect on the gland is 

 produced, and changes, in the same direction as those already 

 described, may be observed. During rest, the cells of the parotid as 

 seen in sections of the gland hardened in alcohol (Fig. 05 A) are 

 pale, transparent, staining with difficulty, and the nuclei possess 

 irregular outlines as if shrunken by the reagents employed. After 

 stimulation of the sympathetic, the protoplasm of the cells becomes 

 turbid (Fig. 65 B), and stains much more readilv, while the nuclei 



FIG. 65. SECTIONS OF THE PAROTID OF THE RABBIT. A at rest, B after stimula- 

 tion of the cervical sympathetic. Both sections are from hardened gland. (After 

 Heidenhain.) 



are no longer irregular in outline but round and large, with 

 conspicuous nucleoli, the whole cell at the same time, at least 

 after prolonged stimulation, becoming distinctly smaller. 



235. In a mucous gland the changes which take place are of 

 a like kind, though apparently somewhat more complicated, owing 

 probably to the peculiar characters of the mucin which is so con- 

 spicuous a constituent of the secretion. 



If a piece of resting, loaded submaxillary gland be teased out, 

 while fresh and warm from the body, in normal saline solution, the 



