106 FUNGI, 



obovate spores, divided by a transverse partition (uni- 

 septate). Sometimes this little Fungus is quite white, 

 at others greenish; when perfectly ripe, the spores 

 become oblong. 



PeniciVlium glaucum (PL VII. fig. 25) is the com- 

 mon Blue Mould found upon decaying substances, as 

 cheese, &c., the interwoven mycelial filaments often 

 forming large cakes or crusts upon the surface. The 

 septate fruit-stalks (fig. 26) are fork-branched at the 

 ends, the branchlets being terminated each by a row 

 of very minute spherical smooth spores. On some 

 decaying substances, as apples, gum, &c., the fruit- 

 stalks are found aggregated into a thick stalk, the 

 branchlets and spores forming a rounded head, so 

 that the whole resembles a little blue mushroom 

 (fig. 27) . In this form the Fungus has been placed 

 in a distinct genus, and called Coremium leucopus. 

 In other species the spores are pink and white. 



This little Fungus is of special interest, on account 

 of one form of it constituting the yeast-plant, or yeast 

 as it is commonly called. This consists of rounded 

 or oblong cells, which grow very rapidly in ferment- 

 ing liquids by budding the large quantity of sugar 

 and gluten present favouring the vegetative or simple 

 growing process, at the expense of the fructifying 

 process. But this is only an instance of what we 

 constantly find in flowering plants, the use of very 

 rich soil rendering flowers double, which is really re- 

 ducing their organs to the state of leaves. When the 

 sugar has become exhausted, the cells of the yeast 

 become longer and thinner, as if starved ; they then 

 form a more recognizable mycelium, which extends 

 to the surface of the liquid, and produces finally the 

 fruit-stalks and the Penicillium fruit. 



Aspergil'lus glaucus (PL VIII. fig. 3) is an ex- 

 tremely common mould upon cheese, jams, &c. It 

 resembles the last in appearance to the naked eye, 

 except that it has rather a green tinge, the heads of 



