26 Mr Langley, On the Secretory Cells and on the [Nov. 12, 



The border-cells (Belegzellen) of mammalian gastric glands, 

 the pyloric gland-cells, and those of the chief cells which are not 

 distinctly granular in life — the exceptions mentioned above — I shall 

 consider separately. 



The secretory cells of all the glands in the list which I have 

 given, have the following common points of structure 1 . 



The cell substance is composed of (a) a framework of living 

 substance or protoplasm, connected at the periphery with a thin 

 continuous layer of modified protoplasm ; the framework in some 

 cases has the form of a network of small threads of equal size as 

 described by Klein 2 ; in others of flattened bands. Further the 

 threads or bands may vary in size in different parts of the cell, 

 and the meshes in different parts of the cell may be of different 

 size and shape. Within the meshes of the framework are enclosed 

 two chemical substances at least, viz. (b) a hyaline substance in 

 contact with the framework, and of (c) spherical granules which 

 are embedded in the hyaline substance. 



In the gland-cells which secrete much organic matter the 

 cell-granules are conspicuous and fairly large. In the gland-cells 

 which secrete comparatively little organic matter, the cell-granules 

 are generally speaking smaller and less distinct, the lower the mean 

 percentage of organic matter is in the fluid secreted. 



The cell-granules are in nearly all cases mesostates, i.e. substances 

 stored up in the cell and destined to give rise to the organic substances 

 of the secretion. The granularity of a cell in the resting state thus 

 depends upon its storage-power. Generally speaking the greater the 

 storage-power of a cell, the higher is the percentage of organic substance 

 in its secretion, but this is not always the case, since it may happen 

 that the rate of secretion of water may increase without any correspond- 

 ing increase in the rate of secretion of organic substance, and in conse- 

 quence the percentage of organic substance in the secretion may be 

 small ; further it is possible that under special circumstances a cell 

 with small storage-power might secrete a large quantity of its stored-up 

 material and that a cell with large storage-power might secrete a very 

 small quantity of its stored-up material, the amount of water secreted 

 by the two cells being approximately equal. 



In all these cells, during active secretion, the following changes 

 take place. The granules decrease in number and usually, if not 

 always, in size ; the hyaline substance increases in amount ; the 

 network grows. The increase of the network is much less than 

 that of the hyaline substance. 



Moreover in the majority of the cells, the details of the changes 

 which take place are much the same. The hyaline substance 



1 This I have already described for the liver-cells (Proc. Roy. Soc. No. 220, 

 Ap. 1882). 



2 Quart. Journ. Mic. Science, Ap. 1879. 



