284 MUCEDINES. PAET n. 



damp paper, old damp linen, dead wood and plants. 

 Their spawn is seldom much developed, the fertile 

 threads are erect, rigid, dark brown approaching to 

 black, sometimes of an olive green. The spores on 

 their tops are either simple, in whorls, or collected into 

 heads, which are large, septate, and even spiral. 



The Mucedines are beautiful microscopic objects both 

 as to form and colour ; they are very numerous both in 

 genera and species and are well known as red, blue, or 

 green moulds. These fungi spring from many points 

 of a generally abundant mycelium, in erect coloured 

 threads, bearing on their tips simple naked spores, 

 spores collected into little tufts, or spores strung 

 together like beads forming threads either branched 

 or simple. In this order of fungi there are, moreover, 

 instances of dualism, the second order of fruit being 

 that of the family of the Ascomycetes. 



The Botrytis, or Peronospora infes.tans, which causes 

 the murrain in potatoes, shows how destructive the 

 Mucedines can be. Like other entophytes, its spores 

 enter the stomates in the leaves of the potato, and fill 

 the cavities of the leaves with spawn, the ramifications 

 of which are said to be very beautiful. This creeping 

 spawn then insinuates itself into the stem and tuber, 

 and from thence it finds its way to the exterior of the 

 plant, or to some internal cavity, where it fructifies, 

 bearing large globose sessile bodies yielding fruit of the 

 second order, and spores on the tips of its fertile 

 branches. The spawn of the Botrytis spreads rapidly 

 in a circle, and soon destroys the texture of the leaves 

 and stem, but although it attacks the tuber or potato 

 generally so called, it does not penetrate deeply. The 

 destruction of the potato is aided and completed by the 

 Fusisporium Solani, a microscopic fungus, which takes 

 various forms according to its age and changing con- 

 ditions, the last of which seems to be partly gelatinous ; 



