THE GENUS ASPERGILLUS. 327 



We need do no more than mention the ascosporogenic A. 

 nichdans (Vuill.), recognised by VUILLEMIN (1.) as a Sterigmato- 

 cystis. 



A. JRekmii, Zukal, and A. pseudodavatus, Puriewitsch, are also 

 species with branched sterigmata. Both of them are rare and of 

 little practical importance, but noteworthy as being among the 

 few reported as producing ascospores, which, however, are quite 

 different from those of A. nidulans. 



Aspergillus Rehmii (see 3 in Fig. 165) was discovered on gall- 

 nuts and decayed oak bark by ZUKAL (I.) in 1893. ^ ne sulphur- 

 yellow to ochreous coat develops d warf conidiophores (0.4-0.5 mm. 

 high), bearing elongated ovoid globules (20 ^ by 30 /z), slender 

 sterigmata, and small globular to ellipsoidal conidia (2.5-4 jj, 

 across). The black, fragile perithecia (0.1-0.2 mm.), the skin of 

 which is formed of a single layer of regularly disposed rows of 

 cells, are surrounded by a compact shell formed of yellow hypha?, 

 which in many cases are swollen into globules. The asci, which 

 are formed immediately, are ovoid, on short stems and rapidly 

 become mucinous, develop elliptical, tough-skinued, smoke-grey 

 spores, measuring 5 /j, by 3.5 p and numbering 8 in each case. 

 The ascospores are formed by the intertwining and fusion of 

 morphologically uniform hyphae. This species may be regarded 

 as doubtful. 



Aspergillus pseudodavatus, Puriewitsch, agrees, in the structure 

 of the conidia (up to the branched sterigmata) entirely with that 

 of A. davatus. The globule measures 260-300 /z by 60-70 /u ; and 

 the greyish green, ellipsoidal conidia, measuring 3.5-4 p by 

 2.5-3 A* are identical in size and shape with those of that species. 

 The small naked globular perithecia, which measure 60-70 JJL in 

 diameter, and are provided with a wall formed of a single layer of 

 cells, enclose only 6-7 asci, each with 8 colourless spores. The 

 perithecium is apparently developed from two hyphae. The 

 optimum temperature of this species, which was discovered on old 

 yeast cultures by PURIEWITSCH (IV.) in 1899, is about 25 C. 



Of the other best known titerigmatocystes we need mention 

 only the following : the brownish yellow A. sidfureus, Fresenius 

 (on bark) ; A. ockraceus, Wilhelm (on bread and damp portions of 

 plants), which develops sclerotia abundantly, but no asci ; the 

 green A. elegans, Gasperini (on decaying lemons); A. variabilis, 

 Gasper ini (on decaying fruit), with both simple and branched 

 sterigmata. Allied to these are a number of more or less doubtful 

 or imperfectly described species, found chiefly on vegetables, 

 and included in SACOARDO'S list (IV.), and also critically sifted 

 by WEHMER (XVII.). The A. ochraceus, described and closely 

 examined by WILHELM (I.), produces a large number of brown, 

 nodular sclerotia, formed by the intertwining and fusion of ordinary 

 hypha3 (as in the case of A. niyer), but not developing asci. This 

 seems to be identical with the A. auricomus of GUEGUEN (I.). 



