14 The Anatomy of the Salivary Glands 



been too scanty for an adequate test of the hypothesis. Secondly, 

 the hypotheses applied have been too simple and limited in scope. 

 As the salivary glands produce a secretion of very complicated 

 composition, it is not at all likely that a simple hypothesis involving 

 secretion or reabsorption of a single ion will account for this secre- 

 tion (see Chapter X). It may be that more sophisticated arguments 

 with statistical evaluation of the cell population may be more 



Fig. 2.4. Distribution of different duct epithelia in human salivary and 

 pancreatic glands. 



Intercalary ducts, black: striated ducts, stippled: excretory ducts, light grey. 

 A, sublingual; B, submaxillary; C, parotid; D, pancreatic (Bouin, P. (1932), Elements d' His- 

 tologic, Alcan, Paris). 



illuminating, but in the kidney, for instance, a study of the com- 

 plex histology has proven to be no help in aiding the understanding 

 of physiological events. Caution must also be used in interpreting 

 cytological changes in gland cells as evidence of a particular secre- 

 tory activity. Degranulation after stimulation does correlate quite 

 well with a decline in protein output (p. 182), but we may not 

 assume that this correlates in any way with the secretion of water 

 or electrolytes, since there is no evidence at the present time of 

 cytological correlation of these secretions. Indeed in the pancreas 

 a dualism between the effects of secretin on water and electrolyte 



