12 THE STRUCTURE OF THE GLANDS OF BBUNNER 



increases daily. The sections fastened to the slide by the water method are treated 

 with benzole and absolute alcohol. The slide is then flooded with the staining solution, 

 placed on the stage of the microscope, and watched until the intense blue color appears 

 in the cells. The sections are then rapidly washed in 95 per cent, alcohol, dehy- 

 drated, cleared, and mounted in xylol balsam. Washing in water extracts the stain, 

 but if the sections are first washed in 70 per cent, alcohol, then in lime water, the 

 stain is fixed, and subsequent washing in water affects it but slowly. Similarly 

 effective results may be obtained with mucicarmine, if the strong stock solution of 

 Mayer be employed instead of the diluted solution. Mucicarmiue can be depended on 

 only if the solution is freshly prepared ; the old solutions do not give satisfactory 

 results. The stain obtained with mucicarmine is very stable, is not affected by washing 

 in water, and may be used for subsequent contrast staining. Very excellent double 

 stains, remarkably rich in detail, are obtained by staining in iron alum htGinatoxylin, 

 followed by mucicarmine. 



Muchsematein, prepared and applied in the way described above, gives an intense 

 blue color to the contents of the goblet cells and of the clear portion of the glandular 

 epithelial cells of Brunner. Old solutions stain the granules of the mast cells and, if 

 the solutions are acid, as Harris has pointed out, the coarser elastic fibers. Cytoplasm 

 remains unstained. Cells stained in this way exhibit the exact reverse of the struc- 

 ture described above, and illustrated in Fig. 2. The clear zones of the cell appear 

 filled with deeply stained secretion, the rest of the cell colorless. 



Considerable interest attaches to the mode of aggregation of the secretion in the 

 cell, and in this connection some results have been obtained which afford a simple 

 explanation of the discordant results on the mucous salivary glands. The writer was 

 at first considerably puzzled by the fact that in some of his preparations the secretion 

 appeared in the form of distinct granules, in others in the form of a continuous coarse 

 meshed network. It was speedily found, however, that if water were excluded from 

 the operations of the technique, the granular condition was always obtained, whereas 

 if water were introduced at any stage, the reticular appearance was obtained. For 

 example, sections stained without fastening to the slide, or after cutting in celloidin, 

 by simply transferring from strong alcohol to the stain, then back to alcohol, gave 

 granules ; sections passed through water, or fastened to the slide by the water 

 method and heat, gave a network. The obvious inference was that the secretion was 

 stored in the cells in the form of fine granules or droplets which had not been altered 

 chemically by the fixing agents, and which on treatment with water promptly went 

 into complete or partial solution, to be again precipitated by the stain in reticular 

 form. It is a well-known fact that mucins outside the cell precipitate frequently in 

 the form of a coarse network. 



We may now return to a description of the cell after staining with mucliBB- 

 matein in such a way as to preserve the granules of secretion. Such a preparation is 

 illustrated in Plate XX, Fig. 3. In each cell there are seen to be two masses of 



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