PHYSIOLOGY 99 



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, and ether; become swollen and later dissolved in boil- 

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

 acid. This substance which composes the refractile bodies is called 

 paraglycogen (Biitschli) or zooamylon. The abundant glycogen bod- 

 ies of Pelomyxa have already been mentioned (p. 91). Rumjantzew 

 and Wermel demonstrated glycogen in Actinosphaerium. In loda- 

 moeba, glycogen body is conspicuously present and is looked upon as 

 a characteristic feature of the organism. The iodinophile vacuole of 

 the spores of Myxobolidae is a conspicuously well-defined vacuole 

 containing glycogenous substance and is also considered as possess- 

 ing a taxonomic value. In many ciliates, both free-living (Parame- 

 cium, Glaucoma, Vorticella, etc.) and parasitic (Ophryoscolecidae, 

 Nyctotherus, Balantidium, etc.), glycogenous bodies are always 

 present. According to MacLennan (1936), the development of the 

 paraglycogen in Ichthyophthirius is associated with the chondrio- 

 somes. In Eitneria tenella, glycogenous substance does apparently 

 not occur in the schizonts, merozoites, or microgametocytes; but 

 becomes apparent first in the macrogametoc3^te, and increases in 

 amount with its development, a small amount being demonstrable 

 in the sporozoites (Edgar et al., 1944). 



Fig. 39. a-d, two types of paramylon present in Euglena gracilis 

 (Biitschli); e-h, paramylon of E. sanguinea, XllOO (Heidt). e, natural 

 appearance; f, g, dried forms; h, strongly pressed bodies. 



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 character- 

 istic 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. 39) is spirally coiled which confirms 

 Biitschli's observation. The paramylon appears to be a polysac- 



