454 THE SALIVARY GLANDS, BY E. F. W. PFLUGER. 



duct is also clear. If a canula be now introduced, and firmly 

 tied in, and the nerves be irritated, the fluid immediately be- 

 comes cloudy ; but when a few drops have been discharged, it 

 again resumes its transparency. The first drops discharged on 

 irritating the nerves, after the introduction of the canula, are 

 those which were already in the duct, and were originally 

 transparent, but have become cloudy whilst still in its interior, 

 for the clear secretion extracted from the freshly excised 

 duct remains clear when exposed to the air. Contact with the 

 wall of the duct has consequently rendered the secretion 

 cloudy. If we examine the first drops microscopically, we shall 

 find they contain isolated cells and groups of epithelial cells 

 with nuclei, unquestionable medullated nerve fibres, connective 

 tissue, etc.; in a word, constituents which have been detached 

 from the mucous membrane of the duct by the canula, and 

 which there is no object in describing further. As soon as a 

 stronger salivary current is induced by excitation of the chorda 

 tympani, these detached elements are completely washed away, 

 the fluid again becomes quite clear, and no longer contains any 

 morphological elements. After a short time, however, they re- 

 appear in sparing number as the so-called salivary corpuscles, 

 that is to say, as small, finely granular, nucleated cells, present- 

 ing in some instances amoeboid movements, whilst the fluid is 

 rendered cloudy by the presence of fine granules. These bodies, 

 however, it may be easily shown, always proceed from the wall 

 of the excretory duct after it has become affected with catarrhal 

 inflammation, and not from the gland ; for if the nerves are 

 irritated sufficiently long to cause a flow of perfectly clear 

 saliva from the india-rubber tube of the canula, and the ex- 

 citation be then interrupted for ten minutes, and, before it is 

 recommenced, the saliva stagnating in the caoutchouc tube 

 from the previous irritation be pressed out, it will be found, when 

 collected, to be as clear as before. If the excitation be now 

 reapplied, we obtain, since the canula is of very small diameter, 

 for the first three or four drops, that which has collected in the 

 excretory ducts from the previous irritation. These three drops 

 are quite cloudy from exudation and detached cells, but are 

 followed immediately by saliva as clear as water ; that is to say, 

 as soon as the exudation has been washed out of the duct. I 



