4 A MANUAL OF THE PENICILLIA 



give little evidence that any one of them actually knew which organism 

 another had described under any of the different names proposed. 



In Penicillium, as in Aspergillus, Corda (1837 to 1839) cleared up some 

 of the uncertainties of structure evident in previous discussions of the 

 genus, but his illustrations idealized the morphology of his species to such 

 an extent that subsequent identification has never been satisfactory. 

 Species of Penicillium are found described in the works of Bonorden, 

 Fresenius, and Preuss during the period about 1850. These authors 

 included with what we now call Penicillium such organisms as Cladosporium, 

 Hormodendrum, or even Monilia sitophila. Few, if any, of the names they 

 proposed can now be recognized as Penicillia. These workers represent a 



Fig. XI. 



::K'o 



JO 



Fig. 1. Bulliard's Plate 504, fig. XI, Mucor penicillatus. The earliest known figure 

 unmistakably representing a Penicillium. 



\'^U'ifI 



period in which the mj^cologist was primarily a microscopist, intent upon 

 describing the specimens which came to hand either as fresh materials 

 from his o^vn environment or as herbarium specimens. A corollary to 

 his work was the assumption that a mold found in any situation was suf- 

 ficiently pure and characteristic to form a safe basis for taxonomic work. 

 No cultures were made. The reactions of one organism to the presence of 

 one or several others were not taken into account. The specimen was 

 described, then labeled and dried for the herbarium, and the description 

 was published whether or not the specimen was recognizable after it was so 

 preserved. Montagne (1856) lamented that no one could find out what 

 organism any of his predecessors used in describing their species, but he 

 failed to offer a more efficient handling. 



The same difficulty is encountered in interpreting the species of Peni- 

 cillium described by Rivolta (1873), Berkeley. (1841, 1875), Berkeley 



