author's abstract of this paper issued by 

 the bibliographic service, november 24 



THE ACCELERATION OF METAMORPHOSIS IN FROG 

 LARVAE BY THYROID FEEDING, AND THE EFFECTS 

 UPON THE ALIMENTARY TRACT AND SEX GLANDS 1 



W. W. SWINGLE 



Department of Zoology, University of Kansas 



FOURTEEN FIGURES 



INTRODUCTION 



Since Brown-Sequard proposed the theory of internal secre- 

 tion, each successive year has produced an increasing number of 

 researches into the nature and function of the endocrinous glands. 

 One of the striking facts brought out by these experiments, is 

 the physiological interrelation of the various secretory organs. 

 One of the most interesting of these relationships, is the ap- 

 parent correlation in function of several of the glands of internal 

 secretion, and the reproductive organs. It is fairly well estab- 

 lished, for instance, that anomalies and diseases of the hypophysis 

 are in many animals intimately associated with abnormalities of 

 the sex glands and sexual development, and it has been assumed 

 by many investigators that the thyroid gland and its secretory 

 products is also physiologically related to these organs. The 

 functional correlation, however, in the case of the thyroid and 

 gonads is much more obscure than the pituitary-gonad relation, 

 and is, at the present state of our knowledge regarding the 

 problem, open to question. 



The results obtained by Gudernatsch, in his experiment upon 

 feeding thyroid glands to tadpoles, by which he was able to pro- 

 duce frogs no larger than flies from immature larvae in a very 

 short time, suggested that frog larvae might be an excellent 

 from for investigating the relation of the thyroid and sex glands. 



1 Reported at the Annual Meeting, 1915, of the American Association for the 

 Advancement of Science, Columbus, Ohio. 



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