THE MOULD-FUNGI. 85 



lowest of these branchings are the longest ; these again 

 develop below their ends one or more short side branches. 

 The topmost branches are almost as wide as they are long. 

 Thus a system of branchings is formed which is shaped like 

 a raceme or a bunch of grapes. When the longitudinal 

 growth is at an end, the inner space of the branches becomes 

 separated from the main stem by the formation of a transverse 

 wall close to the latter. At the same time the ends of the 

 branches and of the main stem swell, and on the upper 

 half of each swelling several small papilla? now appear near 

 together ; these quickly increase to oval blisters, filled with 

 plasma, and become narrowed, stalk-like, at their base. 

 When these conidia (C') are completely developed, the walls 

 of the branches carrying them are shrivelled up, and the 

 conidia are consequently brought so closely together that 

 they form a loose, irregular aggregation which readily falls 

 off. If these clusters are placed in water, the conidia become 

 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 conditions this mould can assume a peculiar 

 state of rest, the so-called sclerotium (skleros = hard) (a, 6, ss). 

 The hyphal threads branch extremely freely, and the branches 

 intertwine themselves into a continuous body of diverse shape, 

 circular to narrow spindle-shape, and of varying size up to 

 a few lines ; 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. Such bodies are 

 capable, after a long period of rest at least one year of 

 forming a new growth, and may in so far be compared with 

 the bulbs and roots of the higher plants. If the sclerotium 

 is brought into a moist place soon after it comes to maturity, 



