94 PROTOZOOLOGY 



in total darkness, although the chromatophores appear somewhat 

 modified. 



The reserve food matter 



The anabolic activities of Protozoa result in the growth and in- 

 crease in volume of the organism, and also in the formation and 

 storage of reserve food-substances which are deposited in the cy- 

 toplasm to be utilized later for growth or reproduction. The re- 

 serve food stuff is ordinarily glycogen or glycogenous substances, 

 which seem to be present widely. Thus, in saprozoic Gregarinida, 

 there occur in the cytoplasm numerous refractile bodies which 

 stain brown to brownish- violet in Lugol's solution; are insoluble 

 in cold water, alcohol, ether; become swollen and later dissolved 

 in boiling water; and are reduced to a sugar by boiHng in dilute 

 sulphuric acid. This substance which composes the refractile 

 bodies is called paraglycogen (Biitschli) or zooamylum. The abun- 

 dant glycogen bodies of Pelomyxa have already been mentioned 

 (p. 90). Rumjantzew and Wermel demonstrated glycogen in 

 Actinosphaerium. In lodamoeba, glycogen body is conspicuously 

 present and is taken as a characteristic feature of the organism. 

 The iodinophile vacuole of the spores of Myxobolidae is a con- 

 spicuously well-defined vacuole containing glycogenous substance 

 and is also considered as possessing a taxonomic value. In many 

 cihates, both free-living (Paramecium, Glaucoma, Vorticella, 

 etc.) and endozoic (Ophryoscolecidae, Nyctotherus, Balantidi- 

 um, etc.), glycogenous bodies are always present. 



The anabolic products of the holophytic nutrition are starch, 

 paramylon, oil and fats. The paramylon bodies are of various 

 forms among different species, but appear to maintain a certain 

 characteristic form within a species and can be used to a certain 

 extent in taxonomic consideration. According to Heidt (1937), 

 the paramylon of Euglena sanguinea (Fig. 37) is spirally coiled 

 which confirms BiitschU's observation. The paramylon appears to 

 be a polysaccharide which is insoluble in boiling water, but dis- 

 solves in concentrated sulphuric acid, potassium hydroxide, and 

 slowly in formaldehyde. It does not stain with either iodine or 

 chlor-zinc-iodide and when treated with a dilute potassium hy- 

 droxide, the paramylon bodies become enlarged and frequently 

 exhibit a concentric stratification. 



In the Chrysomonadina, the reserve food material is in the 

 form of refractile bodies which are collectively called leucosin, 



