THE PARS BUCCALIS OF THE HYPOPHYSIS 7 



ing season unsuccessful attempts to transport living frog eggs 

 from the Middle West were made. Finally favorable material 

 was secured from the rather scanty local anuran fauna by col- 

 lecting the adult pairs of the frog, Rana boylei, at the time of 

 laying. The larvae of this form proved ideal, wounds healed 

 rapidly, feeding was vigorous, and growth uniform. 



An astonishing result of this early removal of the epithelial 

 hypophysis was now revealed. Characteristic, silvery-colored 

 larvae — albinos — in great contrast to their darkly pigmented 

 normal mates, resulted. Similar results were obtained simul- 

 taneously by B. M. Allen. In a series of papers the writer, 

 B. M. Allen, E. R. and M. M. Hoskins, and W. C. Atwell have 

 further confirmed and sought to analyze this discovery. Allen 

 has subsequently studied in more detail the changes induced 

 by an equally early ablation of the thyroid gland. No one, 

 it would appear, has endeavored to confine his attention to the 

 altered anatomy and physiology displayed by these pituitary- 

 free 'albinos.' The present monograph aims to do this. While 

 brief statements of some of its material have appeared from time 

 to time, there has been collected here for the first time as com- 

 plete an account as is now possible of the pigmentary upset 

 and other correlated bodily changes, especially endocrine alter- 

 ations called forth by this procedure. 



The conditions of the experiment 



All amphibian material is not equally favorable for work of 

 this nature. In order to assure prompt healing, the yolk must 

 be moderate in amount and of a cohesive nature. Thus oper- 

 ative work upon the larvae of the common newt, D. torosus, is 

 precluded, due to its large, abundant, and non-cohesive yolk 

 granules, which extrude for hours through the wound, even 

 final healing being prevented. The unfavorable character of 

 the Ambly stoma punctatum for work of this nature has pre- 

 viously been commented upon by Harrison. For studies on 

 growth it is further essential that the animals be vigorous feeders 

 and develop at a rather uniform rate. This desideratum would 



