THE CELL 23 



when treated with iodine. It is a hydro-carbon com- 

 pound, and is considered by Errera as reserve material of 

 equal value to fungi as starch is to chlorophyll producing 

 plants. 



Fibrosin bodies is the name given by Zopf to certain 

 minute discoid or cone-shaped bodies present in the 

 conidia of Podosphaera oxyacanthae. These again are 

 hydro-carbon reserve material, and are insoluble except 

 in concentrated mineral acids. 



Volutin is the name given by Meyer to certain minute 

 spherical bodies met with mostly in the cytoplasm, where 

 they are of constant occurrence in many families, and are 

 also met with in considerable abundance in most groups 

 of plants. This reserve material is considered to be of 

 special importance, for in addition to the C, H, and O of 

 fats and carbon-hydrates, it also contains N and P atoms 

 in its composition. The most general test for its presence 

 is a deep blue colour on the addition of one part of 

 Ehrlich's methylene blue in ten parts of water, added to 

 one part of concentrated sulphuric acid in ninety-nine 

 parts of water. 



Oxalate of lime is an abundant product, although but 

 rarely occurring in cells. On the surface of cells it is of 

 common occurrence, as on the pilei of Agarics, Coprinus 

 micaceuS) Psilocybe atomata, etc. The sporangial walls of 

 many species of Mucor are also incrusted with a layer of 

 very minute crystals. Under the form of minute needles 

 or amorphous particles, it is not uncommon on or in the 

 substance of the walls of young vegetative hyphae. In 

 vegetative hyphae of Ithyphallus impudicus^ certain large 

 globose or flask-shaped vesicular cells are almost filled 

 with a radiately crystalline mass of oxalate of lime. 



