VITAL STAINING OF AMCEBOCYTE TISSUE. 2Q3 



As to the relation between the diffuse protoplasmic staining and 

 the granule staining, two views have been expressed, (i) Both 

 the staining of granule and the diffuse staining of protoplasm 

 depend upon the same process, namely, the solubility of the dye 

 in lipoids of the protoplasm as well as of the cell granules (E. 

 Nirenstein 4 ) ; and (2) the staining of granules and protoplasm 

 differ, inasmuch as the diffuse staining of the protoplasm depends 

 upon the lipoid solubility of the stain, while the granule stain is 

 due to a chemical combination between the basic radicle of the dye 

 and an acid constituent of the granule, which latter is presumably 

 not of a lipoid character (W. v. Moellendorff 5 ) . One argument on 

 which the second view is based consists in the difference in the 

 effects of alkali and acid on the staining of the protoplasm and of 

 the granules. Addition of weak alkali increases the solubility of 

 the dye in lipoids and is therefore believed to favor a diffuse 

 staining of the protoplasm by neutral red. Addition of acid, on 

 the other hand, diminishes the solubility of the dye in lipoids and 

 it is assumed by W. v. Moellendorff that this is the reason why acid 

 prevents the diffuse staining without destroying the staining of 

 the granules. Our experiments prove that the amcebocytes 

 behave differently in this respect: addition of alkali intensifies, 

 while addition of weak acid causes a rapid loss of the granule 

 stain. The protoplasm is not noticeably affected, as far as its 

 staining is concerned, by either alkali or acid. Our observations 

 show therefore that the staining of the granules is affected by 

 acid in the same way as is the protoplasm in certain other cases, 

 and we 'would therefore conclude that a distinction between the 

 staining of these t\vo cell constituents cannot be based on the 

 argument w T hich we have just cited. 



3. According to our observations weak acid decolorizes very 

 rapidly the granules of amcebocytes previously stained by neutral 

 red, while alkali intensifies the staining. As we have seen, the 

 effect of acid and alkali on the staining properties of neutral red 

 has been referred to the influence w r hich acid and alkali exert on 

 the lipoid solubility of neutral red. 



On the other hand, Pelet and Andersen 6 have shown that the 



4 E. Nirenstein, Pfliiger's Arch., 1920, Bd. 179, 233. 



6 W. v. Moellendorff, Ergebn. d. Physiol., 1920, XVIII., 141. 



6 L. Pelet and N. Andersen, Zeitschr. f. Kolloidchemie, 1909, II., 225. 



