FIELD E 

 Columns 18, 19, 20, 21, 

 22, 23, 24, and 25 



Specific Directions and Explanations 



Separately Outlined for the Use of Symbols for 



Test Organisms, Tumors, and Pathologies in Field E 



I. TEST ORGANISMS ( Taxonomy Code ) 



1. Definition 



By the term "test organism", reference is made to the organism against which the action of 

 the test compound is directed, when this organism is not affected with a pathology or tumor which is 

 itself being specifically treated. This term does not refer to any organism which is used in a test as 

 the experimental host . (See Parts II and IV of this section for a discussion of tumor and pathology 

 coding. ) 



2. Taxonomic categories below species are not distinguished by code in Field E 



The code symbols for test organisms are exclusively in the Taxonomy Code of Field E. These 

 symbols permit taxonomic distinction of phyla (or plant divisions), classes, orders, families, genera, 

 and species, but not strains or varieties. Therefore, when all conditions are the same except that two 

 or more varieties are used, lines can not be constructed for results on each variety, since the coding 

 in Field E would only be identical for each variety in each line and the lines would appear to be mere 

 repetitions or contradictions of each other. (An exception to this is permitted by use of Symbol F in 

 Field G, only under conditions as described in Division 4 below. A second rare exception is made by 

 the eighth unit of the symbol as explained in Division 5 below. ) 



3. Physiological strains may be indicated by code, but not in Field E 



The preceding paragraph points out that the Code does not distinguish taxonomic categories 

 below species. However, physiologically distinct strains of a species frequently occur and a general 

 provision has been made for distinguishing certain of these by code. This provision consists of items 

 in Field G (Symbols F; G, H, and I; 6 and J). Examination of these items of Field G will explain the 

 extent of strain distinction possible. Field E by itself does not provide for strain distinctions any 

 more than for taxonomic varieties. 



4. Several taxonomic varieties or physiological strains tested by the identical test methods ; 

 coding procedure 



In the case of data from tests on a number of taxonomic varieties or physiological strains, 

 only a single code line should be constructed for all the organism forms showing a positive response, 

 regardless of the degree, using the indiscriminate evaluation criterion, "Author's Evaluation", Symbol 

 01 in Field X, and the general evaluation, "Active", Symbol in Field Y. If none of the varieties or 

 strains of the series tested responded to the test compound (i. e. , if the responses of all organisms 

 were negative), the evaluation in Field Y would be "Inactive", Symbol 1. If only a few of the series 

 of organism varieties or strains showed a negative response, code one line combining those showing 

 a positive response; code a single line, combining those showing a negative response; test-organism- 

 distinction between these two lines is made by coding, in the line for the negative responses , Symbol F 

 in Field G. (See Field G, Specific Directions and Explanations, Division 9. ) 



5. Exceptional use, by the CBCC, of the eighth unit of the Taxonomy Code for indicating a 

 variety or strain 



Although the CBCC has largely adhered to the provisions explained in Divisions 2, 3, and 4 

 above, restricting the use of the eighth place of the Taxonomy Code symbols to designating species, 

 an occasional exception has been allowed. When a particular taxonomic strain (e.g. , cabbage: 

 Brasslca oleracea capitata ) or a physiological strain (e. g. , the DDT-resistant housefly) is so exten- 

 sively used experimentally that (1) many lines of data will be coded for it and (2) there would be con- 

 siderable advantage in being able to retrieve information on that strain by a single file sort, the strain 

 is given a unique code symbol just as if it were a distinct species. If all information on the housefly, 

 for example, is subsequently to be retrieved from a file of coded data, not only must the search be for 



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