THYROID REMOVAL IN LARVAE OF RANA PIPIENS 



513 



TABLE 4 



DATE KILLED 



DIMEN- 

 SIONS 



Controls 



Thyroidless 



FT1 

 FT2 

 FT3 

 FT4 



December 6 

 December 6 

 February 14 

 March 6 



0.157 

 0.184 

 0.147 

 0.178 

 0.197 

 0.255 

 0.206 

 0.235 



In the later stages, as the ovary became very irregular in form, 

 no further attention was paid to the thickness, because such 

 measurements would have very little value. 



A study of the table measurements shows that the ovaries of 

 the thyroidless tadpoles have continued to increase in size with 

 the passage of time until they have reached a volume well in 

 excess of that of the young normal frogs killed a short time after 

 metamorphosis. The following comparison is instructive. 



Average estimated volume of ovaries of FCl, FC2 and FC3 1 .5762 



Average estimated volume of ovaries of FT1, FT2 and FT3 6.5122 



