KEY TO THE ORDERS AND FAMILIES OF FUNGI IMPERFECTI 603 



Penicillium, later determined to be P. riotatum Westl., and in 1929 he gave 

 the name penicilHn to the active substance. His experiments demonstrated 

 that it would destroy many species of bacteria in cultures to which it was 

 added, while many other kinds of bacteria were unharmed. Dr. Florey, of 

 Oxford, about ten years later, his interest having been aroused by Dr. 

 Fleming, tested the effect of the injection of penicillin into the blood 

 stream of laboratory animals which had been inoculated with pathogenic 

 organisms which had been found by Fleming to be destroyed by penicillin 

 in culture. The result was marvelous and the animals recovered. Then it 

 was tried on Man with promising results. The result is the widespread 

 commercial production of penicillin on a wholesale basis, using improved 

 strains of P. notatum as well as of P. chrysogenum Thom, in media and 

 under conditions that produce many times more of the penicillin than in 

 the original experiment. Aspergillus has been observed to produce anti- 

 biotic substances but up to the present the products have shown harmful 

 effects when injected into the blood stream of animals. Probably some 

 strain of this genus may be discovered eventually that will lack the harm- 

 ful factor. Noting that some of the forms related to Actinomyces, e.g., 

 Streptomyces as delimited by Waksman and Henrici (1943), also seemed 

 promising in this regard various soil inhabiting species of this group were 

 studied and from one of them was selected a strain which produced the 

 substance to which the name streptomycin has been given. This also is of 

 great value in medicine since it destroys in the body many organisms 

 which are not affected by penicillin (see Fleming, 1946; Duemling et al., 

 1946; Herrell, 1945). 



What the role of these antibiotic substances is in the fungi that pro- 

 duce them is not yet clear. That these are in the nature of waste products 

 has been suggested. They reach their maximum production in relatively 

 young (4 to 7 days), actively growing cultures, well supplied with oxygen. 

 The production is greatly increased by the addition of certain organic 

 substances which possibly stimulate the growth of the fungi. This is a 

 matter that must be left for the researches by mycologic physiologists. 



Key to the Orders and Families of Fixngi Imperfecti^ 



Asexual spores regularly produced. 



Spores produced in pycnidia; other types of spores may sometimes be present. 



Order Sphaeropsidales 

 Pycnidia complete, with or without an ostiole, sometimes representing 

 merely pycnidial cavities in a stroma. 

 Pycnidia (or stroma) dark-colored, usually rather hard. 



Family Sphaeropsidaceae 

 Pycnidia (or stroma) bright-colored, usually fleshy or leathery. 



Family Zythiaceae 



■* Note that these groups are with few exceptions artificiarand do|not represent 

 phylogenetic relationships. 



