AUTHOR S ABSTRACT OP THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, DECEMBER 23 



STUDIES ON THE RELATION OF lODIN TO THE 



THYROID^ 



I. THE EFFECTS OF FEEDING lODIN TO NORMAL AND 

 THYROIDECTOMIZED TADPOLES 



W. W. SWINGLE 



Fellow in Biology, Princeton University 



CONTENTS 



Introduction , 397 



Literature 398 



Material and methods 400 



Observations (Feeding of iodin compounds to normal larvae) 401 



1 . Potassium iodide ' 401 



2. Iodin crystals 405 



3. Iodoform 409 



Feeding iodin to thyroidectomized larvae 411 



Summary and conclusion 414 



INTRODUCTION 



Early in the spring, while carrying on a series of feeding ex- 

 periments with tadpoles, the writer suggested to Mr. A. C. 

 Eitzen, a student in the Medical School of the University of 

 Kansas, that he undertake the problem of feeding inorganic 

 iodin, and various organic compounds of this substance to frog 

 larvae. The object was to note the macroscopic effect upon 

 growth and metamorphosis and the histological effects on the 

 thyroid and germ glands. 



Most of the investigators who have dealt wth the problem 

 of the relation of iodin and its compounds to the activity of the 

 thyroid have used mammals as experimental material, forms 

 which, in the author's opinion, offer no such sure and certain 



' The experimental work for this paper was done while the writer was in- 

 structor in zoology at the University of Kansas. Acknowledgment is made to 

 this laboratory. 



397 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 27, NO. 3 



