CYTOPLASMIC INCLUSIONS 129 



respond to the "vacuome de reserve" of Volkonsky and the segregation 

 apparatus of Kedrowsky. The segregation granules of necessity still 

 include a heterogeneous assortment and probably include granules other 

 than those associated with synthesis and storage, but at present they 

 cannot be classified properly because too many of them are known only 

 by their ability to segregate neutral red. Kedrowsky and Volkonsky 

 regard both types as carriers of enzymes, in one case acting to digest 

 proteins and in the other case to synthesize them. However, each group 

 appears de novo when the necessity arises, and the two groups show 

 no direct continuity with each other. Further evidence of the independ- 

 ence of these two groups of granules is furnished by Opdina, in which 

 only the segregation bodies are present, and by Ichthyophthir'ms, in which 

 only the digestive granules are present, these latter having no connection 

 with the storage of the numerous protein granules. 



Digestive Granules 



The digestive granules may be briefly defined as cytoplasmic granules 

 stainable with neutral red, which become associated with the newly 

 formed vacuoles containing food. This does not include all neutral 

 red granules in the food vacuole, since such granules as the vacuole 

 refractive bodies of Amoeba are derived from the food (Mast and 

 Doyle, 1935b) and thus are not cytoplasmic components. Volkonsky 

 (1934) points out that the term vacuole has been applied to so many 

 structures that it is a source of confusion, and he has substituted the term 

 gastriole. The fluid vacuole which contains ingested food is a pro- 

 gastriole, and with the addition of the digestive granules (vacuome in 

 Volkonsky's terminology) becomes a gastriole. In addition to these 

 terms it is convenient to use postgastriole for the structures containing 

 undigested remnants. 



There is no single pattern of the gastriole in the Protozoa. In 

 A. proteus, mitochondria alone aggregate periodically around the gas- 

 triole (Mast and Doyle, 1935b); in Paramecium and Campanella, the 

 digestive granules enter the gastriole, and mitochondria cluster around 

 the membrane in the alkaline phase; in Flabellula, the materials stain- 

 able with Janus green or neutral red are normally dissolved in the fluid 

 vacuole, which later forms the gastriole (Hopkins, 1938), and a some- 

 what similar situation is found in hypermastigote flagellates (Duboscq 



