2 7 6 



HARRY DEAL TORREY AND BENJAMIN HORNING. 



Fifty-two Brown Leghorn chicks, hatched March 27, were 

 divided into four groups as indicated in Table I.: two control 

 groups (one with and one without gonads); two experimental 

 groups (one w r ith and one without gonads). A week later, on 

 April 3, the rectrices of all were pushing out. On that date 

 daily doses of 16 mgm. of desiccated thyroid (Armour's, con- 

 taining 0.2 per cent, iodine) in capsule by mouth, were begun 

 for one group of normal chicks (Nos. 36-50). On April 17, the 

 dosage was increased to 32 mgm. and given to the second experi- 

 mental group (Nos. 51-63) also. 



TABLE I. 



Gonadless Controls. 



Gonadless Thyroid-fed Chicks. 



