232 BOTANICAL MICROTECHNIQUE. 



form of a hollow cone or a hollow cylinder (cf. Fig. 56). 

 Their largest diameter varies from 2 to 

 8 }JL. No stratification can be observed 

 in them, even after treatment with caus- 

 tic potash or chromic acid. For the 

 examination of the fibrosin bodies Zopf 



FIG. 56. Fibrosin - bodies , , . , . . . 



from the conidia of Podo- recommends that they be isolated by 



sphagra oxyacanthcg^^r\.\-y 



in different views as indi pressure on the cover-glass, or that the 



cated by the dotted lines. 



(xiooo). After Zopf. spores be made more transparent with 

 nitric acid or caustic potash. Zopf has determined the 

 following points as to their chemical relations : They 

 swell in hot water into roundish bodies ; they are colored 

 neither by iodine-potassium-iodide solution nor by chloro- 

 iodide of zinc ; neither are they dissolved by the latter re- 

 agent. In concentrated sulphuric acid they are soluble with 

 difficulty ; they are not dissolved by nitric acid, even after 

 48 hours' exposure. In caustic potash they are insoluble 

 in the cold, but, on warming in it, they swell up into irregu- 

 lar, strongly refractive bodies. They are insoluble in cu- 

 prammonia, alcohol, ether, and chloroform, are not browned 

 by osmic acid, and take up no aniline dye. 



The fibrosin-bodies therefore agree most closely in their 

 reactions with fungus-cellulose, and are distinguished from 

 the cellulin-grains especially by their insolubility in chloro- 

 iodide of zinc and their difficult solubility in concentrated 

 sulphuric acid. A macrochemical analysis has not yet been 

 carried out, for obvious reasons. 



14. The Mucus-globules of the Cyanophyceae. 



416. Several authors have observed globular structures in 

 the cells of the Cyanophycea, which always lie in the periph- 

 eral part of the protoplasm (Fig 57, s) and are often es- 

 pecially abundant on both sides of the transverse walls. 

 These may be here termed, with Schmitz, mucus-globules, 

 although no conclusion as to their chemical composition 

 is at present possible. 



417. According to the recent investigations of Zacharias 



