320 MORPHOLOGY OF THE ASPERGILLACE^. 



(similar to a gun sponging-rod, and measuring 150 ^ by 35 /*), 

 such as are observed in A . pseudoclavatus (with branched sterig- 

 mata) and A. giganteus ; and was described by DESMAZIERES (I.), 

 in 1834. The short,, simple sterigmata (about 8 //by 3/1) see 

 Fig. 174 divide by constriction into small, oval (not globular!), 

 smooth conidia (4.2 by 2.8/z) in long chains, enveloping the 

 elongated heads with a greyish green dust. The length of the 

 conidiophore stems, which are 15-25 JJL thick, reaches about 2 cm., 

 but seldom exceeds that figure. 



Other species mentioned in the literature as occurring on 

 plants are the large, greenish yellow A. penicillopsis (Hennings), 

 RACIBORSKI (II.), as well as the dwarf, olive-coloured A . Delacroixii 

 (Delacroix), Saccardo and Sydow, observed by Delacroix on cocoa 

 beans. Both these species deserve further investigation. Among 

 other well-known species we will only mention the green 

 A. varians, Wehmer, A. mini mis, Wehmer (observed on leaves 

 and on sugar solutions), and A. ostianus, Wehmer (found on 

 leaves and boiled rice), which latter species is characterised by 

 a pale ochreous pigment. There are also a number of more or 

 less completely described species, chiefly observed on vegetables, 

 and for the most part not yet cultivated, including the new 

 A. calyptratus and A. Koningi, OUDEMANS (II.) and A. citrisporus, 

 F. von HOHNEL (I.). 



As a giant among its kind, mention may also be made of 

 Aspergillus giganteus, Wehmer (XVII.). The conidiophores 

 of this fungus (which grows on sour wort) resemble those 

 of A. clavatus in the shape of the globules and sterigmata, and 

 attain an average length of 1-2 cm., and therefore about ten 

 times that of most of the other species. Before the heads begin 

 to colour, the herbage has a mucor-like appearance, and it is 

 only later that it is clearly distinguishable from the greyish 

 yellow or dark mucor vegetation by the greyish green tinge of 

 the conidial heads (1000 by 120-125/1) on their slender, pale, 

 saffron-yellow stems. The short sterigmata (9-12 by 4-5/1), 

 which are invariably simple and thickly cover the surface of the 

 globule (500-800^ by 80-100^), produce comparatively small, 

 smooth, oval conidia, measuring on the average 4 // by 2.6/j. 

 The species thrives on the usual substrata at room temperature 

 and is easily cultivated. A noteworthy feature is the readily 

 detectable perforation of the wall of the globule below the 

 sterigmata, in the form of a narrow channel (when viewed in 

 section, and a tiny circle when viewed in plan) appearing inside 

 the larger one corresponding to the diameter of the sterigma, 

 and causing the globule to seem as though covered with small 

 concentric circles (see Fig. 163, 1 1). No perithecia have yet been 

 observed. 



