210 



CORA J. BECKWITH 



In indifferent killing fluids (alcohol, neutral formalin, hot water) 

 the reversed staining reaction of the granules must be due to 

 some other cause than the presence of the acid. It is possible 

 that mere precipitation changes the chemical composition of 

 the granules, giving it an affinity for basic dyes. 



Similarity in staining reaction for the identifying of materials 

 has long be questioned. The physical and chemical nature of 

 staining processes has been ably discussed by many writers (Fisher 

 '09, Hardy '99, Lilienfeld '93, Heidenhain '11, Nemec '10, Mathews 



TABLE 2 



Vital stains and digestion tests 

 Young eggs 



! Sections or fresh material were digested in artificial gastric fluid (1 per cent pepsin in 0.2 per cent 

 HCl) at body temperature from two to three hours. In the adult egg the yolk and mitochondria are 

 digested, leaving a framework of protoplasm. Millon's reagent shows that some proteid from the proto- 

 plasm of the young egg is removed while the pseudochromatin-granules are not affected. 



2 The fixation is so poor that the mitochondria cannot be identified . 



