702 A MANUAL OF THE PENICILLIA 



PeniciUium through Thidavia and Microascus to Chaeiomium. The asco- 

 sporic phase of these fungi, no lees than the conidial stage, is deserving of 

 more careful study. 



Occurrence and Significance 



Members of the genus Scopulariopsis, and particularly S. hrevicaulis 

 (Sacc.) Bainier, are unusually abundant in nature. They are isolated regu- 

 larly from soil. They are fairly tolerant of drought and commonly appear 

 upon materials such as stored grain, forage products, and all types of semi- 

 dry vegetation undergoing slow decay. They often develop upon organic 

 residues after the readily available nutrients are exhausted, and after most 

 other micro-organisms have completed their roles in the decomposition 

 process. They thrive on substrata that are relatively rich in nitrogen and 

 are commonly isolated from products of animal origin including leather, 

 wool, bone, cured meats, and ripening cheese. Members of the genus are 

 sometimes isolated from insects (Sartory, el al., 1930). Strains are not in- 

 frequently isolated from skin and nail infections, and less commonly from 

 other parts of the body. Many species have been described as parasitic 

 or semi -parasitic. 



Biochemically, the group is of considerable interest because of the ca- 

 pacity of most strains to attack arsenic compounds with the evolution of 

 arsenical gases characterized by a garhc odor. Occasional cases of arsenic 

 poisoning of individuals living in houses with walls painted or papered with 

 arsenic containing pigments, such as Scheele's green, were first reported 

 more than a century ago. Such deaths were at first attributed to the in- 

 halation of pigment particles as dust. Later some investigators suggested 

 that the molds growing upon the walls might play an active role. Gosio, 

 in the 1890's, was the first to make a systematic study of the whole ques- 

 tion. He found PeniciUium brevicaule Sacc. to be quite active, and de- 

 veloped a method for detecting minute traces of arsenic in different ma- 

 terials, the mold producing a more or less intense garlic odor in the presence 

 of arsenic. Gosio's work was continued by his associate BigineUi (1900) 

 who concluded that the volatile gas was diethylarsine. Meanwhile Maa- 

 sen (1902), Huss (1914), and others reviewed the matter of arsenic evolu- 

 tion and its possible relation to pathological symptoms. 



The whole question of mold induced arsenic poisoning was brought to 

 a sharp focus by the so-called ''Forest of Dean Case" in 1932, wherein the 

 death of two children in Wales was suspected of being due to arsenic poison- 

 ing (see Lerrigo, 1932). Analysis (jf body tissues showed the presence of 

 arsenic, and exposure of filter paper saturated with silver nitrate to the 

 air of the room gave a positive test for arsenic. An investigation of the 

 subject of gaseous arsenic evolution by molds was initiated at the University 



