PLASMA-STRUCTURE IN EGG OF HYDRACTINIA 213 



gested sections, are run back to back through staining jars to 

 ensure similar treatment, the granules in the digested sections 

 after staining with iron-hematoxylin, take the stain much less 

 intensely than those of the control slide. Also after Auerbach's 

 stain the granules are grayish in the digested material,, rather 

 than green as in the undigested sections. 



Still another point suggests that there may be other materials 

 than chromatin in the cell which may not be digested by peptic 

 digestion. In sections placed in a digestive medium in which 

 the acid content is strong 0.5 HCl and digested either a long 

 time (18 to 20 hours) at room temperature, or a short time (2 

 to 3 hours) at body temperature, all the material in the nucleus 

 is digested while the granules remain undigested. This confirms 

 the impression that the granules are of a different nature from 

 chroniatin. Again, the failure of a certain material to be digested 

 by peptic digestion is not necessarily a proof of its chromatic 

 character, since peptic digestion depends on the degree to which 

 a substance is penetrated and therefore on the density of the 

 material. In the above case it is possible that the acid aids in 

 the penetration of the nuclear material but is unsuccessful in 

 penetrating the granules. On this basis peptic digestion is no 

 test for chromatin. Since pancreatic digestion digests the whole 

 cell, it is evident that an alkaline medium is essential for the diges- 

 tion of the pseudochromatin-granules. 



7. Millon's proteid test also is in harmony with the possible 

 chromatin nature of the granules. Before digestion, young 

 eggs containing granules (as well as mature eggs) give the typical 

 brick red reaction very strongly, while no proteid test is obtained 

 after digestion, although the granules are still present as stated 

 above. The proteid reactions in the undigested egg must then 

 be given either by the protoplasm or some proteid associated with 

 the granules, rather than by the granules themselves. 



8. Attempts to locate chromatin by testing for histone as 

 described by Mann ('02) were only partially successful. The 

 results, however, support the view that the granules are not the 

 same as the chromatin. The strongest color reaction indicating 

 the presence of histone occurred in the nucleus, while the proto- 



