Chapter VI 

 USE OF THE MANUAL 



The purpose of this Manual is two-fold. First, it is designed to facilitate 

 the identification of Penicillia as these are isolated from nature, and as they 

 are encountered, or utilized, in the laboratory, in agriculture, or in industry 

 in connection with special problems. Second, it is designed to introduce 

 to the user a summary of whatever information has accumulated regarding 

 the physiology, biochemistry, pathogenicity, or other characteristics of 

 individual species and groups. The latter type of information is given 

 special consideration under paragraphs entitled "Occurrence and Sig- 

 nificance" at the close of each series discussion. Often additional refer- 

 ences covering the same type of subject matter are included in the Topical 

 Bibliography (Chapter XVI). 



In this Manual, recognized species of Penicillium are considered in 

 limited groups, or Series, which for the most part are believed to represent 

 natural groupings. Series believed to be naturally related are in turn 

 grouped to form larger subdivisions, or Sections. The identification of 

 species is important and should be accomplished wherever possible. Fortu- 

 nately, for many types of work, recognition of the series is sufficient to 

 characterize general cultural and morphological structures, and oftentimes 

 to indicate general physiological behavior as well. For this reason, and 

 because of intergradations between closely related species, the series concept 

 is stressed particularly. 



Data for Identification 



In a very limited number of cases Penicillia can be correctly assigned to 

 series or even to species by the examination of specimens taken directly 

 from naturally moldy materials. In the vast majority of cases, however, 

 cultivation in the laboratory under standardized conditions is imperative. 

 To identify successfully any Penicillium, certain information must be ob- 

 tained and carefully analyzed. To facilitate the collection of this essential 

 information we have found a standardized data sheet to be most useful. 

 This guarantees that all pertinent information will be included, and also 

 insures that this data will be listed in a uniform and orderly manner. The 

 information collected should present a comprehensive picture of the cultural 

 and microscopic aspects of the strain being studied or identified. The 

 comparison of different species, or the comparison of unidentified strains 

 with recognized species, is thus greatly facilitated. 



For convenience, essential data may be indicated vertically upon a 



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