Vol. XXXII. March, 1917. No. 3. 



BIOLOGICAL BULLETIN 



EFFECTS OF THE EXTIRPATION OF THE ANTERIOR 

 LOBE OF THE HYPOPHYSIS OF RANA PIPIENS. 



BENNET M. ALLEN. 

 UNIVERSITY OF KANSAS. 



These experiments were performed in the spring of 1916, 

 although attempts had been made the previous year which failed 

 because of faulty technique. 



Adler ('14) removed the hypophysis ingrowth by using the 

 electric cautery at a stage of 20 mm. length. This caused im- 

 mense mortality and he was able to rear only 3 specimens. In 

 these the hind limbs did not grow beyond the condition of mere 

 buds and persisted in this condition long after metamorphosis 

 of the controls and many months after the operation. He found 

 that the growth of the thyroid gland was markedly retarded by 

 the removal of the hypophysis and the amount of colloid was 

 much reduced. 



P. E. Smith performed quite similar experiments simultan- 

 eously with mine. Both of us gave simultaneous accounts of our 

 respective researches before the San Diego meeting of the 

 Western Society of Naturalists August 9 to 12. He published 

 his results in Science, August 25, 1916, and in the Anatomical 

 Record, October, 1916. I gave a preliminary account of my 

 work in Science November 24, 1916. Since I have been delayed 

 in making this more complete report, I can allow myself the privi- 

 lege of drawing comparisons between Dr. Smith's work and my 

 own. 



My account of the experiments upon the hypophysis was de- 

 layed owing to the fact that I was absent from Lawrence during 

 the summer and was unable to complete the study of my material 

 until my return in September. I had also hoped to combine the 



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