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THE POPULAR SCIENCE MONTHLY 



For the last place in this brief enumeration we have reserved one 

 of the most common of household moulds. It is the prince of moulds, 

 and claims relationship with the most perfect and beautiful of fungi. 

 In diet it is something of an epicure, and may well be called the cake 

 and preserve mould, .and on those substances the best results are al- 

 ways obtained when used for its culture. Though preferring its cake 

 and preserves, it was induced to grow on a tempting dish of stewed 

 prunes, which afterward furnished the substance for its culture. 



To the naked eye this mould at first appears as white patches ; soon 

 stalks rise from the surface, and on the end of each a small spherical 

 head is borne, which increases in size and turns to a bluish color, so 

 that when this mould is ripe the surface of the nourishing substance 

 does not differ greatly in color from the Penicillium on the bread, 

 though this mould is much taller and more inclined to grow in tufts. 

 Under the microscope the tip of a very young filament which is to 

 form a head of spores is seen to be perfectly smooth and similar to 

 those in the 3Iucor, but very soon small peg-like projections begin to 

 grow from its surface, which increase in size and finally divide, formino- 

 radiating rows of spores. 



Fig. 12. Eurotium Aspergillus glaccus. De Bary. 



Fig. 13. 



Various stages in the development of the asexual fruiting of this 

 mould are shown in Fig. 12, a, a, with a view of an imaginary cross- 

 section through one of these heads highly magnified in b, giving the 

 method of attachment of the spore-threads. 



Shortly after the heads have formed, the sexual fruit begins to de- 

 velop on the mycelium at the base of the fruit-stalks. The method is 

 more complicated tlian in any of the moulds already given, and places 

 this plant among the most highly developed of fungi. The process 

 begins with the coiling of the end of a thread in a corkscrew manner 



