76 



they are mounted on slides and the paraffin has been removed, may 

 be used. For the pieces of tissue more time is required than for the 

 sections. Sections need be left in the bichromate solution only from 

 5 to 20 minutes. After the bichromate solution the material is washed 

 in water and the further treatment is the same as if the tissue had 

 been fixed originally in Zenker's fluid. Sections fixed in formalin, 

 alcohol-formalin or Flemming's fluid, stain with the Mallort stain 

 precisely as if they had been fixed at the first in Zenker's fluid. The 

 same may be said of Van Gibson's stain, with the exception that it 

 cannot be used after fixation in Flemming's mixture. 



2. Mallory's Stain as a Differential for Mucin. 



Most of the mucus stains require rather elaborate technique. 

 There is room for a quick and easy difi"erential for mucin. Mallory's 

 anilin blue connective tissue stain in many ways answers this require- 

 ment. It is not as difterential as are the mucihaematin and muci- 

 carmine stains. These stain little besides mucin. Mallory's mixture 

 stains collagen, amyloid and certain other hyalin substances the same 

 deep blue it does mucin. However, after the mucin has once been 

 diflerentiated in one of two sections by the rather difficult muci- 

 haematin or mucicarmine methods, it is of great advantage to have a 

 rapid and intense stain like Mallory's mixture to use for all further 

 identification. 



With the Mallory stain mucin and collagen stain blue, nuclei 

 and elastic fibers yellow, cytoplasm, myofibrillae and fibroglia fibrillae 

 red, premucigen granules yellow, red or blue depending upon how 

 nearly they approach mucin in composition. 



Mallory's stain was used on the mucus cells of the stomach, 

 small intestine and large intestine of Necturus, dog, pig and man, 

 Brunner's glands of pig, the salivary glands of dog and the mucoid 

 tissue of human umbilical cord. In all this material the mucin stains 

 blue ; that of the stomach epithelium, of the intestinal goblet cells and 

 of the salivary gland cells intense blue, that of Brunner's glands light 

 blue. Mallory's mixture stains especially well the mucus cells of the 

 stomach. The mucin here, probably because of the acid reaction, is 

 notably hard to stain with the ordinary differentials. With the anilin- 

 blue stain it is colored just as readily and just as intensely as is that 

 of the goblet cells of the intestine. 



Mallory and Wright in Pathological Technique, 1908, mention 

 that the Mallory stain colors mucus blue. Hammar, "Arch. f. mikr. 

 Anat.", 1909, used the stain to show the mucus cells in the thymus. 



