DISTRIBUTION OF THE NERVES IN THE SALIVARY GLANDS. 445 



lated nerve. It cannot, consequently, give off any process 

 which is a connective tissue fibre, or which is continuous with 

 connective tissue cells; for between animal tissue and con- 

 nective tissue substance there cannot be any continuity of 

 substance. 



Inasmuch as I am now satisfied that the multipolar cells are 

 continuous through their processes with nerve fibres (fig. 89), 

 it follows that they must either be modified epithelial cells or 

 ganglion cells. Their continuity with nerve fibres does not 

 decide the question, since the salivary cells also present' this 

 character under the most various modifications in common with 

 true nerve cells. 



There consequently remain, as means for determining the 

 point, only analogy and anatomical structure. To whatever 

 degree the multipolar cells may differ amongst themselves in 

 their size and form, and in the characters of the nucleus and of 

 the protoplasm, as indeed was observed by Boll, they neverthe- 

 less resemble nerve cells more closely than epithelium, as is 

 shown by the fact that small ganglion cells have been admitted 

 to occur amongst them by various observers, as by Henle and 

 Krause. In the next place, in regard to the great variation 

 that they present, it is important to remember that if the 

 alveoli, as we have decisively proved, undergo continuous 

 regeneration and disintegration, the nervous tissue must be 

 subject to similar metamorphoses. The nucleus in some of 

 these remarkable cells is round, as was also observed by Boll ; 

 and is at the same time transparent, and almost entirely fills 

 the cell. This peculiarity is presented also by other peripheric 

 ganglia, as the granules of the rods and cones of the retina, 

 which unquestionably represent bipolar nerve cells. Moreover 

 these cells exhibit a pale striated protoplasm, the fibres of 

 which may be followed into the similarly striated, and in parts 

 highly refractile, cylindrical processes. Such cells consequently, 

 taken as a whole, exactly resemble, and would be held by all 

 to constitute, ganglion cells. 



Besides these, we find other cells with ellipsoidal or flat 

 nuclei, which are partly round and partly present flat processes 

 and membranous cell substance, and are quite transparent. 

 Finally, there are still others, lying within the young alveoli 



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