THE MOULD-FUNGI. 107 



filament takes the form of a helix (the ascogonium). There 

 then grow from the lowest turn of the helix two or more small 

 branches, which cling closely to the spiral. One of these 

 (S, T, p) quickly outstrips the others in growth ; its upper 

 extremity reaches the uppermost turn of the helix, and fuses 

 with it. The other branch or branches likewise grow upwards 

 along the spirals, shoot out into new branches, and gradually 

 become so interlaced that the spiral is finally surrounded by 

 an unbroken envelope (W). These branches divide slowly 

 into septa perpendicular to the surface, and the envelope 

 consequently consists of short, angular cells, in which new 

 septa appear parallel to the surface, so that the envelope 

 thickens and is composed of many layers (V, X, F). The 

 small sphere now formed is about one-quarter mm. in 

 diameter ; the outermost layer is yellow, whilst the inner 

 layers remain soft, and later are dissolved. The spiral after 

 a time extends and throws out on all sides branched filaments, 

 which dislodge the inner layers of the envelope. These 

 branches finally take the form of an ascus (M and A), eight 

 spores being formed in each. After the breaking up of the 

 asci the spores lie loose in the interior of the perithecium, and 

 are liberated by the rupture of the fragile wall of the latter. 

 The spores, as in the case of Penicillium, are bi-convex, warty, 

 and possess a stout outer membrane and an inner one, which, 

 on germination, bursts the outer membrane forming two 

 valves (?*). 



Eurotium Aspergillus glaucus contains a diastatic ferment, 

 which converts starch into dextrin and maltose. 



In addition to this species, several others, closely related, 

 occur in nature, and also find their way into the factory. 



Thus, according to COHN, it is Aspergillus fumigatus that 



FIG. 28. Eurotium Aspergillus Glaucus (DE BARY) : m, in, hyphal thread, carrying a 

 conidiophore c (from which the conidia have fallen), a perithecium F, and the first 

 rudiments of an ascogonium, /(x 190); s, three sterigmata from the crown of a coni- 

 diophore, showing the conidia-constrictions ; p, germinating conidium ( x 250 300) ; 

 A, Ascus ; ?, germinating ascopore; k, germ tubes ; S, spiral ascogonium ; at p the 

 commencement of the growth of one of the enveloping hyphaj ; T, older stage ; W, 

 ascogonium, already surrounded by the envelope ; V, longitudinal section of an older 

 stage ; in the centre the ascogonium, surrounded by the envelope, which now consists 

 of several layers ; A', longitudinal section of a later stage of development ; the 

 ascogonium is enveloped in a sheath of many layers ; it has loosened its convolutions, 

 and is beginning to throw out the ascus-forming branches ; M, portion of an older 

 ascus-bearing branch ; a, a young ascus ; a,, an older ascus which has burst. 



