100 MICEO-ORGANISMS AND FERMENTATION. 



the upper half of each swelling several small papillae appear 

 close together ; these quickly increase to oval blisters, filled with 

 plasma, and grow narrow, stalk-like, at their base. When these 

 conidia (6 y/ ) are completely developed, the walls of the branches 

 carrying them are shrivelled up, and the conidia are con- 

 sequently brought so closely together that they form a loose, 

 irregular aggregation which readily falls off. If these clusters 

 are placed in water, the conidia are detached from their stalks, 

 and the envelopes of the branches, devoid of plasma, shrivel up 

 or are only to be found in traces ; their former place of attachment 

 to the main filament appears only as a slightly raised scar. 

 The member next below can now throw on one side the 

 shrivelled apex, grow upwards, and form a new cluster ; this 

 can be repeated several times, whereby the conidiophores attain 

 a considerable length. Under certain nutritive conditions the 

 conidia and spores develop short threads from which small 

 bright round conidia are separated, either directly or on bottle- 

 shaped basidia. 



Under certain conditions this mould can assume a peculiar 

 dormant state, the so-called sclerotium (skleros = hard) (a, b, ss). 

 The hyphal threads branch extremely freely, and the branches 

 intertwine themselves into a continuous body of diverse shape, 

 circular to a narrow spindle-shape, and of varying size ; the 

 extreme ends of the filaments are brown to black, and the ripe, 

 solid sclerotium thus consists of an outer black rind and an 

 inner colourless tissue. These bodies, which were described by 

 DE BARY under the name of Sclerotinia Fuckeliana, appear as 

 small black corpuscula occurring on the herbaceous parts of 

 many plants, where they live as parasites or saprophytse. 

 They are capable, after a long period of rest lasting at least 

 a year of forming a new growth. If the sclerotium is brought 

 into a moist place soon after it comes to maturity, the 

 inner colourless branches break through the black outer rind 

 and throw up the conidiophores (a). If, however, the sclerotium 

 is not brought into a moist place until after it has been 

 at rest for some time, a large tuft of filaments develops from 

 the inner tissue, and these shoot up perpendicularly and 

 finally spread out to a flat, plate-shaped disc (b and ps) ; the 

 ends of the filaments appear parallel on the free upper surface 



