372 R. E. BENSLEY. 



pure rubin stain. Furthermore, washing in alcohol after stain- 

 ing in safranin will extract the safranin from the prozymogen, 

 and, as Macallum ^ pointed out, from the oxyphile nucleolus, 

 long before it is extracted from the basophile chromatin of the 

 nucleus. I have made use of this property in connection with 

 the hsematoxylin iron reaction to determine the distribution of 

 prozymogen in the glandular cells of the stomach. In working 

 with the hsematoxylin method alone one is often in doubt 

 whether an apparent reaction is a real one, or simply the 

 result of a nucleus lying in an upper or lower plane of the 

 section, and out of focus, acting as a light filter. If, however, 

 the section after treatment with the hsematoxylin be well 

 washed and transferred to a dilute solution of safranin in 30 

 per cent, alcohol, then extracted in alcohol until the safranin 

 is nearly all removed, cleaned in benzole, and examined, it is 

 found that whilst the nuclear chromatin has taken on a red- 

 dish-blue tinge from the safranin, the oxyphile nucleolus and 

 the prozymogen have retained a slaty-blue colour, which it 

 is impossible to mistake even in thick sections (fig. 5). 



The fibrillated appearance presented by the outer clear zone 

 of the chief cell is of adventitious origin, and not in itself of 

 importance. A study of the mode of growth of the zone 

 shows that the first indication of an increase of protoplasm 

 is a thickening of the trabeculae separating the granule- 

 containing spaces in the outer ends of the cells. Then, 

 as the granules disappear from the outer ends of the cells, 

 this thickening becomes more apparent, and affects more par- 

 ticularly those trabeculse which are arranged in a direction 

 parallel to the long axis of the cell, so that these give in 

 optical section the impression of longitudinal bars or fibrillse. 



The fine fibrillation which Eberth and Miiller,^ Mouret,^ 

 and others figure in the pancreatic cell may be seen in the 

 gastric chief cell, only in the small amount of unused proto- 

 plasm which is usually seen in the resting cell. This not 



' ' Quart. Journ. Mic. Science,' vol. xxxviii, part ii, new series. 

 ^ ' Zeitschr. f. wissenscli. Zool.,' Bd. liii, supplement. 

 » Op. cit. 



