FIELD X 

 Columns 69 and 7 



FIELD Y 

 Column 71 



Field X 



Field Y 



30 Weight of the thyroid gland, expressed in 

 terms of milligrams of thyroid gland per 

 100 grams of body weight. 



The evaluation with Criterion 3 is based 

 on the ability of the test compound to 

 decrease the thyroid activity, as indi- 

 cated by the gland's hypertrophy. Thus, 

 the greater the gland's hypertrophy, the 

 greater should be the test compound code 

 evaluation. 



<8 thru 8 



>8 thru 16 



> 16 thru 24 



>24 thru 32 



>32 



31 Iodine content of the thyroid gland, ex- 

 pressed in terms of milligrams of iodine 

 per 100 grams of thyroid gland. 



The evaluation with Criterion 31 is based 

 on the ability of the test compound to 

 decrease iodine in the thyroid. Therefore, 

 the smaller the quantity of iodine in the 

 gland, the more is the test compound's 

 anti-thyroid ability. 



1 >40 



3 >20 thru 40 



5 > 10 thru 20 



7 >5 thru 10 



9 <5 thru 5 



Note: Criteria 51, 52, 53, 54, 57, 58, 59, and 55 are 

 used only when the data include information on the 

 percentage of individuals responding to each dose level 

 of test compound (Criteria 51, 52, 53, and 55) or to 

 each duration of response, increase of survival time, 

 etc. (Criteria 54, 57, 58, and 59). For evaluations by 

 these eight criteria, the Log-Probit Grid must be used. 



51 



52 



53 



Concentration expressed in Field M vs. 

 cumulative percentage of individuals 

 responding. 



Quantity expressed in Field N vs. cumula- 

 tive percentage of individuals responding. 



Duration of administration expressed in 

 Field P vs. cumulative percentage of 

 organisms responding. 



Consult the Key for the explanation of the 

 use of the Grid and the use of these three 

 criteria with which Field Y is coded with 

 one of five symbols: 



1 



These five symbols represent positive 

 response from "low" (large dose and/or 

 few individuals responding) to "high" 

 (small dose and/or most or all individuals 

 responding), regardless of the intensity 

 of response in the individual (e. g. , per- 

 centage increase of heart rate, percentage 

 change of rate of development). Criteria 

 51, 52, and 53 are used mostly for eval- 

 uating the test compound's lethal activity 

 on a group of individuals of the test 

 organism. 



188 



