FIELD X 

 Columns 69 and 70 



FIELD Y 

 Column 71 



Field X 



Field Y 



59 Killing time (the time period from beginning 

 of administration to the point of death, 

 coded in Field U), vs. the cumulative per- 

 centage of individuals killed within the 

 time period coded in Field U. 



With Criterion 59, evaluation is based on 

 the percentage of individuals killed after 

 a given period of time. (Study the example 

 given in the Key, Specific Directions and 

 Explanations for Fields W, X, and Y, Divi- 

 sion 20. ) Evaluation symbols: 1, 3, 5, 7, 

 or 9, according to the Grid area involved. 



55 Antagonism dosage vs. Incidence of antag- 

 onism in a group of individuals. Dosage 

 (concentration, quantity, or duration of 

 administration) of test compound causing 

 antagonism of the biological action of the 

 secondary compound vs. the cumulative 

 percentage of individuals in which that 

 dosage causes antagonism. 



Note: Evaluation by Criterion 55, of a 

 test compound's ability as an antagonist 

 of the specific action of a given secondary 

 compound is not modified by the degree of 

 antagonism (i.e., partial reduction of the 

 response to the secondary compound). 

 Criterion 55, as well as Criterion 22, should 

 be used only when the secondary compound's 

 action has been prevented (100% reduction 

 of the response to the secondary compound). 



If antagonism is demonstrated only in an 

 individual (the test not demonstrating inci- 

 dence of antagonism in a group of individ- 

 uals), use Criterion 22. 



Ratio: 



For Criterion 55, the two quantitative 

 dosage values are related by the following 

 ratio: 



Minimum amount of test compound 



(antagonist) needed to antagonize the 



secondary compound's action lOoy., 



Amount of secondary compound 



whose effect is antagonized 



100% (i.e., prevented) 



The value derived from the above calcu- 

 lation is placed on the abscissa of the 

 Grid with the assistance of the following 

 table of ranges: 



Grid abscissa 

 segment 



Ranges of minimum test com- 

 pound quantities needed to 



antagonize one unit of 

 the secondary compound 



Each of the nine ranges above represents 

 one of the nine equal segments of the 

 scale of the abscissa of the Grid. The 

 dosage ratio value should be located on 

 the abscissa scale at the appropriate 

 point within the range (i. e. , within the 

 abscissa scale segment) indicated in the 

 table above. 



Evaluation symbols: 1, 3, 5, 7, or 9, 

 according to the Grid area involved. 



190 - 



