394 A MANUAL OF THE PENICILLIA 



Sopp, publishing under the name of Johan-Olsen (1898), appears to have 

 been one of the first to suspect the importance of these molds, as evidenced 

 by his isolation and discussion of them under such designations as P. aro- 

 maticum casei, P. aromaticum "I" and "11", "Gammelost", and "Roque- 

 fort". He failed, however, to describe these adequately, and he declined 

 to distribute cultures to other investigators working in similar fields else- 

 where. While closer identification is impossible under the circumstances, 

 we can safely assimie that he was dealing with members of the P. roqueforti 

 series showing the usual range of strain variation. His subsequent Mono- 

 graph on Penicillium (1912) did little to clarify his earlier confusing nomen- 

 clature. 



Diercloc in 1901 published his brief description of Penicillium atro-viride, 

 based upon a mold which Biourge (1923) subsequently held to be the same 

 as P. roqueforti Thom. Dierclcx's description was, however, too inadequate 

 for subsequent recognition. 



Thom (1906) was the first to conclusively demonstrate the significance 

 of these molds in cheese production, and was likewise the first to present an 

 adequate description of the responsible species. Hence, Penicillium roque- 

 forti Thom has come to be generally recognized as the principal species 

 directly concerned with the production of cheeses of the Roquefort type, 

 and constitutes the center around which the present series is based. 



Biourge maintained that Dierckx had intended Penicillium atro-viride 

 to include all the fungi connected with the production of such cheeses as 

 Roquefort, Gorgonzola, etc. He added further that if a collective name 

 could be applied to the whole series of closely related strains, it should be 

 P. atro-viride rather than P. roqueforti Thom. However, since no one has 

 been able to decide from his description just what type of organism Dierckx 

 intended by his P. atro-viride, the name may be justly dropped except for 

 its possible historical interest. Biourge applied the name Stellata to this 

 general series to emphasize the contrast between the smooth, even or regular 

 margin of the colonies of P. chrysogenum and its allies (his Radiata) and 

 the more or less uneven or irregularly developing colonies of P. roqueforti 

 and related species. Wliereas the name is somewhat applicable, it seems 

 to us to exaggerate the appearance actually encountered. Furthermore, 

 the development of a more or less stellate pattern is not confined to this 

 single series of molds as Biourge implied. 



Biourge (1923), Arnaudi (1928), Bainier (1907), and others have de- 

 scribed additional species and varieties closely related to Penicillium roque- 

 forti upon the basis of cultures isolated from other named cheeses of the 

 Roquefort type or upon the cultural characteristics of individual strains. 

 Examination of their descriptions and figures, and in most cases comparison 

 of their type strains as well, has failed to show differences beyond those 



