66 



AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



Trichothecium. — A common pink mold occurring particu- 

 larly on decaying fruit such as apples is Trichothecium 

 roseum. In some cases it may cause considerable damage 

 due to the development of rot. The spores are not un- 

 common and sometimes the mold makes its appearance 

 on laboratory media. The mold itself is white in color, 

 sends up numerous unbranehed conidiophores which pro- 

 duce a cluster of two-celled pear-shaped spores at the tip. 

 The spores do not occur in chains. The terminal cell of the 

 spore is larger than the basal cell. 



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Fig. 45. — Trichothecium. 



Hormodendrum and Cladosporium.— These molds are 

 abundant upon decaying paper, straw, and similar mate- 

 rials. They usually produce irregular dark or sooty 

 patches of various sizes. The mycelium and spores are both 

 smoky or fuscous in color. The conidiophores are usually 

 well differentiated, branching more or less at the tip and 

 producing chains of spores which likewise branch. These 

 two molds belong to the group in which the terminal spore 

 is the youngest in the chain. The most common species is 

 the Cladosporium herbarum. The mycelium frequently 

 produces many cells of irregular shape and size. The coni- 



AAA. Growing on pomaceous fruits 

 (apples, pears). Blue-green colonies 

 forming coremia P. eccpansum. 



