Sidney Klein 325 



tohiidene blue and orange-rubin, the basal cytoplasm of practically every 

 cell exhibits a radial striation which is exactly similar to that described 

 in various sero-zymogenic gland cells by Bensley, Solger, Gamier and 

 others. This character is well illustrated in fig. 3 which is from a speci- 

 men stained in the toluidene blue-orange-rubin method. The basal 

 filaments stain intensely in toluidene blue, less intensely in iron haema- 

 toxylin, but may be observed without difficulty in sections stained with 

 alum-haematein. The most effective method of demonstrating the basal 



FIG. 4. Gland of Lieberkiilm of guinea-pig. From preparation treated by 

 Macallum's method for the detection of masked iron; Leitz 1/12, Oc. 4. 



filaments is by means of the microchemical reaction for organic iron of 

 Macallum, because the result is not confused by the faint protoplasmic 

 stain which is obtained generally in staining with toluidene blue. This 

 method consists in liberating the iron from its organic combinations by 

 treatment of sections from material hardened in alcohol with a solution 

 of sulphuric acid in alcohol for several hours at 37.5 C. and then 

 demonstrating the iron at the point of its liberation by means of haema- 

 toxvlin (see Macallum,, 95). The result, as far as the Paneth cells are 

 concerned,, is a strong reaction in the substance of the basal filaments and 

 in the nuclear chromatin (fig. 4). In some of the Paneth cells a more 



