ROBERT RUSSELL BENSLEY 13 



granules corresponding to the two clear zones of the cells of the preceding figure. 

 The granules in the distal mass bordering on the lumen are very closely aggregated, 

 very small, and somewhat angular in outline. Those of the proximal mass are less 

 closely packed, often somewhat scattered, smaller and more rounded. 



If we now combine the results of the two methods of staining, we may conceive 

 the clear secretion-filled zones of the fixed cell to be composed of two elements, strands, 

 threads, and delicate laminae of cytoplasm, forming a network, in the meshes of which 

 are minute granules of secretion, the latter separated from one another, sometimes by 

 the threads of cytoplasm, more often by clear spaces. This appearance may be inter- 

 preted in one of two ways. In the living cell the granules of secretion must be sepa- 

 rated from one another by a continuous substance of some kind. This continuous 

 separating substance may be either the cytoplasm or a third substance of a more 

 watery nature, filling the interstices of the cell between the particles of secretion and 

 the cytoplasm. In the former case the strands of cytoplasm seen in the dead cell 

 would represent merely the contracted precipitates produced in the continuous cyto- 

 plasm by the fixing reagents ; in the latter case they would represent the actual distri- 

 bution of the cytoplasm in the living cell. The latter interpretation seems the more 

 probable for a number of reasons. In the first place, it suggests a possible explanation 

 of the capacity of the cell to vary the respective constituents of its secretion in response 

 to specific stimuli, the possibility of which has been clearly demonstrated by the work 

 of Pawlow (1898) and his pupils on the stomach, and by that of Malloisel (1902) on 

 the submaxillary gland. In the second place, one frequently sees granules with minute 

 threads of substance stainable in mucha3matein projecting from their surfaces suggest- 

 ing that there is an intermediate clear substance (the hyaline substance of Langley) 

 in which portions of the secretion of the cell exist in complete solution. A third reason, 

 perhaps a stronger one than either of the two foregoing, is that one finds the secretion in 

 the form of droplets or granules in the theca of goblet cells from some sources, in which 

 strong staining in iron hsematoxylin shows the presence of only faint, delicate threads 

 of cytoplasm, or of none at all. 



A glandiilar tubule from a section fastened to the slide by the usual water method 

 and stained in muchsematein is represented in Plate XXI, Fig. 8. The granules of 

 secretion have disappeared and have given place to the coarse network usually seen in 

 mucous cells. The division of the accumulated secretion into an inner and an outer 

 mass may still be recognized in some of the cells, although the bridge of protoplasm 

 separating these is less obvious in the midst of the deeply stained secretion. This net- 

 work again is not of an alveolar character, as the laminae and trabeculae which form it 

 are perforated and interrupted in such a way that the clear spaces throughout the 

 mass communicate with one another. 



The blue-stained network observed in muchsematein preparations is a precipitation 

 product, and must not be confused with the network visible in the clear zones of cells 

 stained by the iron-haematoxylin method. The mucinoid material is doubtless precipi- 



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