AUTHOR'S ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIBLIOGRAPHIC SERVICE, NOVEMBER 24 



THE EFFECT OF THE EXTIRPATION OF THE THY- 

 ROID UPON THE THYMUS AND THE PITUITARY 

 GLANDS OF RANA PIPIENS 



JAMES B. ROGERS 



Department of Zoology, University of Kansas 



ONE PLATE AND TWO CHARTS 



This problem was worked out in the laboratory of the Zool- 

 ogy Department of the University of Kansas under the direc- 

 tion of Dr. B. M. Allen in connection with other problems con- 

 cerning the experimental removal of glands of internal secre- 

 tion from Rana pipiens. Due credit is given for advice, 

 material, and assistance, all of which have been of great help. 



The thymus and the pituitary glands of a number of 

 specimens of Rana pipiens in different stages of development 

 were measured and drawn with camera lucida and comparisons 

 made with thyroidless specimens. 



The thymus is a paired gland found on the sides of the 

 head of the frog just posterior to the tympanic membrane. In 

 section the thymus appears as a round, compact mass of 

 deeply staining cells with a darker outer portion and an inner 

 part that stains somewhat lighter. The characteristic thymic 

 corpuscles are found in the frog thymus. The general appear- 

 ance is that of lymphoid tissue but it is characterized by the 

 thymic corpuscles. The thymus usually degenerates when 

 sexual maturity is reached but may last through the life of the 

 individual. The thymus is now considered as of lymphoid 

 character but with the function of an organ of internal secre- 

 tion that has to do with normal growth and sexual develop- 

 ment. The thymic corpuscles are interpreted by some as the 

 portions that have the secretory function (Bell '05). l It has 

 been regarded as the original source of the leukocytes (Beard 



1 Bell, E. T. 1905. Am. Jour. Ainit., vol. 5, pp. 29-62. 



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THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 24, NO. 3 



