YEASTS AM. Mi iri.I,.-. 



Saccharomyces niger (Black 7W)._<vli, 



MOII.D-KI XGI OR HYPHOMYCETES. 



The mould-fungi have been divid.-d into 

 five orders : Hypodermii, Phycomycetes, Asco- 

 mycetes, Basidiomycetes and Myxomycete. 

 The following species, with the orders to 

 which they belong, are of especial inter, - 



HYPODERMII. 



Ustilago carbo (Milh.r, Smut). Spores 

 brown, circular ; episporium smooth ; sporidia. 

 ovoid cells. The spores or conidia occur as 

 a black powder in the ears and panicl* > 

 wheat, barley and oats. 



Tilletia caries. Spores round, pale 

 brown ; episporium with reticulated thicken- 

 ings. In germinating, the sporidia grow 

 out radially from the end of the promyce- 

 lium ; these, at their lower part, conjugate 



I i i , r '' 231. Bi ' 



by a cross branch and separate from the , 



promycelium, and at some point of the pair .v POTATO. 



a hypha grows out, on which abundant 



secondary sporidia develop. The latter are long, oval o-lN. \\hich 



can in turn germinate. The fungus occurs in the form of a 



stinking powder in grains of wheat, which renders i im- 



pure, and gives it a disagreeable smell. 



Urocystis occulta. The spores consist of several cells united 

 together; partly, large dark-brown evils in the interior, and 

 side, several flat, semicircular, colourless cells. Tin- pn.inyr.'Iiuin 

 germinates as in Tittetia, but the cylindrical evil- pn-lm-.- a li\ ; 

 without, as a rule, previous conjugation. T :r as a M 



powder in rye-straw in long disintegrated stripes, which are at i 

 greyish. The affected plant produces abort i\- I 



Empusa muscse. A spore or conidiirra of thi^ huigus 

 alighting upon the white area of the un-l.-i -mt'an- .t' the body 

 of the house-fly germinates into a hypha. The latter, penetrating 

 the skin, forms toruloid cells, which multiply by germ 

 are disseminated in the blood throughout the body of the fly. 



