MODE OF INVESTIGATING THE SALIVARY GLANDS. 4G1 



fissures are composed of connective tissue fibres, and I have 

 observed them to be lined by an indistinct endothelium. 

 Nevertheless, I have, up to the present time, found no func- 

 tional peculiarity connected with these structural features. I 

 do not in the least doubt that the fissures belong to the 

 lymphatic system, as Gianuzzi maintains. Nothing definite 

 is known in regard to the anatomy of the bloodvessels, which 

 stand in such a remarkable relation of dependency to the ner- 

 vous system, nor yet in regard to the lymphatic vessels. The 

 capillaries wind around them in close contact to the membrana 

 propria forming a very close plexus, derived from different 

 quarters, and show no points of difference from the ordinary 

 arrangement. 



9. MODE OF INVESTIGATION. If it be desired to obtain a 

 general view of the arrangement of the alveoli, excretory ducts, 

 cells, and stroma, fine sections should be made of hardened 

 glands. The hardening is best effected by placing thin portions, 

 whilst still warm from the body, in absolute alcohol. Fine 

 sections can then be made, tinted as usual with carmine, and 

 examined in glycerine. In order to study the finer structural 

 relations, every method of hardening must be avoided. Sections 

 made with very sharp knives of the perfectly fresh gland, can be 

 examined in iodized serum, or in chromic acid containing from 

 25 to 50 per cent., to which a little iodized serum has been 

 added. When thin sections, thus made, are carefully broken up 

 with needles, isolated alveoli may be obtained, with salivary 

 tubes, epithelial cells with nerve terminations, and the like. 

 The isolation of the epithelial cells is best effectedby the appli- 

 cation of iodized serum, in which the gland has been allowed to 

 macerate for from four to six days, or still better, by treatment 

 with iodized serum, subsequent to maceration in chromic acid 

 of one half per cent. The chromic acid macerates the glands 

 most advantageously, if one or two glands have previously been 

 lying in it for one or two days. When quite freshly applied, 

 the volume of this reagent should not exceed from two to four 

 times the volume of that of the gland. Another method of 

 isolating the elementary constituents, especially of the glands 

 in the rabbit, consists in placing the latter in a small test tube, 

 and adding from four to eight drops of solution of chromic acid, 



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