IDS 



,1 Manual of Veterinary Physiology. 



During the stage of rest in a living serous gland, the cells 

 are found to be filled with a quantity of granular material, 

 and the outline of each individual cell is indistinct ; the 

 lumen of the gland is also occluded, and no nucleus can be 

 observed in the cells ; in other words, the gland is char! 



J&% 







Fig. 



Parotid durini 



-Changes in the Cells of tiii 

 Secretion. 

 A, at rest ; B, in the first stage of secretion ; C, after prolonged 

 secretion (Foster, after Langley). 



with its secretory products (Fig. 5, A). During activity 

 the cells get rid of their granular material, which gradually 

 passes towards the centre of the acinus or lumen, leaving 

 each cell with a clear outer edge, whilst that edge next 

 the lumen is still granular (Fig. 5, B). In an exhausted 



Fig. 6.— Cells from Mucous Gland. 



a, from loaded gland ; b, from discharged gland ; a'. b\ treated with 

 dilute acid ; a', from loaded ; b', from discharged gland. 



condition the cells are remarkably clear, only a few granules 

 being left in them on that edge next the lumen, which 

 latter is now distinct and large, and the nuclei are clearly 

 scon occupying a central position (Fig. .">, ( '). 



If a mucous gland at rest be examined under like condi- 



