THE GENUS ASPE11GILLUS. 323 



with other mould fungi. BEHRENS ^XVI.) states that it not 

 infrequently exerts an injurious action in germination tests on 

 seeds, inoculation tests having resulted in stunting the embryos 

 of numerous species, so that a pathological character is assumed 

 in these circumstances. Tiie numerous chemical influences of 

 this fungus, including the very decided capacity for producing 

 oxalic acid, are described more fully in chapter Ivii. LINOS- 

 SIER (II.) states that the, presumably ferruginous, black pigment 

 (the so-called aspergillin) is of some physiological importance in 

 the life of the plant ; but this is doubtful in view of its nature as 

 an excretion product of the conidia, although both MOLISCH (I.) 

 and KANTER (I.) assert that iron is indispensable for the fungus. 

 Greater interest seems to attach to the yellow pigment in the 

 hyphse, examined by MILBURN (I.). Here we can only refer 

 briefly to a whole series of recent investigations by CZAPEK (III.), 

 R,. CHODAT and BACH (I.), RACIBORSKI (II.). LODE (I.), ONO (I.), 

 HATTORI (I.), KNY (II.), BOURQUELOT and HERISSEY (II.), 

 SAIDA (I.), IWANOFF (I.), KOSINSKI (I.), KICHTER (I.), EMMER- 

 LING (V.), LUTZ (II.), FRIEDEL (I.), MAXIMOW (I.), KOSTYT- 

 SCHEW (I.), KQERNICKE ( [.), KANTER (!.),HEINZE (II.), JOUSSET (I.), 

 ORLOWSKI (I.), MOLLIARD and COUPIN (I.), KURZWELLY (I.), 



KOSJATSCHENSKOW (I.), LESAGE (IV.), PANTANELLI (I.), Al/TEN- 



BURG (I.), CHARPENTIER (I.), KRASNOSSELSKY (I.), E. MEISS- 



NER (I.), PORODKO (I.), R. MEISSNER (IV.), TODUR (I.), GAR- 



NIER (I.), and COUPIN (I.), dealing with the chemical composition, 

 nutrition, respiration, the production of enzymes, influence of 

 stimulants, radiation, resistance of the conidia to injurious 

 influences, &c. The literature on this fungus previous to 1901 

 has been collected by WEHMER (XVII.), who gives no fewer than 

 79 references. The numerous enzymes produced by this fungus 

 are dealt with in the next chapter. 



Fungi allied to A. niger occasionally inhabit the interior of 

 certain fruits. Thus, Corda found in dates a species which he 

 named Ustilago phcenicis the Asperyillus phcenicis of PATOUI- 

 LLARD and DELACROIX (I.), who identified it as a species of 

 Sterigmatocystia, and HENNINGS (II.) also recognised as a Steriy- 

 matocystis (St. ficuum), the Ustilago ficuum discovered by 

 HEICHARDT (I.) in dried figs. According to G. VON LAGER- 

 HEIM (I.), the two have since been found to be identical. The 

 question now arises whether this date and fig fungus, which has 

 not yet been compared, in pure cultures, with A. niger, is really 

 different from the latter. This point is by no means clear ; and 

 a short description of the fungus may be given here, on account 

 of its injurious effect on the fruits in question. Accoiding to 

 HENNINGS (II.), the conidiophores fill the interior of the figs with 

 a compact black mass of conidia, arid their heads measure 76-100 yu 

 in diameter, the globule being 45-60 p across, and closely set 

 with club-shaped primary sterigmnta (15-28 by 6-9 p). The 



