102 A PLAIN AND EAST ACCOUNT 



THREADY FUNGI. 



THE fourth group contains the Hyphomycetes, in 

 which the threads are the principal feature. These 

 threads, which bear the naked spores, are white, brown, 

 or coloured, and the best known examples are those 

 which bear the common name of Moulds. These are 

 amongst the most insatiate of the fungoid race ; scarce 

 anything escapes them ; dead fungi or dead spiders, 

 meal or sugar, cheese or onions, pears or oranges, linen 

 or glass. Mouldy cheese may be relished, and pains 

 taken to engraft or bud the plant upon others, yet the 

 moulds are not always so harmless. In certain species 

 they are decidedly poisonous. Turpin says that milk 

 arrested for some time in the udder of a cow was found 

 to contain mould, and species of fungi belonging to this 

 group are not unfrequent in the lungs and stomach of 

 the human subject in certain conditions of disease. 

 The yeast-plant is a fungus, or, to speak more pre- 

 cisely, a kind ofPenicillium, growing and 

 increasing almost indefinitely, and by a 

 species of chemical action producing fer- 

 mentation in any saccharine matter with 

 which it is mixed. When microscopically 

 examined, yeast will be found to consist 

 O f a multitude of ovoidal cells contain- 

 ing a, nucleus. The fresh yeast consists of these indi- 

 vidual cells ; but after being mixed with the wort of 



