Effects of Albation on Endocrine Glands. 8i 



in hypophysis-free albinos present a greatly expanded condition 

 and that this expanded condition is not amenable to most exper- 

 imental influences (temperature and light) although anesthetics 

 affect it. An exactly opposite physiological state of these cells, 

 i. e., a contracted condition, usually occurs in the normal larvae. 

 Successful skin exchanges altered the state of the xantholeucophores to 

 correspond to that characterizing the new host. The change is 

 usually observable within fifteen minutes and is invariably com- 

 plete within four hours. Inasmuch as the change is much more 

 pronounced than that exhibited by animals of weakened vitality 

 or immediately after death, it can hardly be referable to merely a 

 transient condition of weakened vitality. More especially is this 

 the case, since the changes taking place terminate only when the 

 state of the transplanted xantholeucophores fully corresponds to 

 that characterizing the new host. 



The rapidity with which these changes take place would 

 appear to establish the fact that the expanded physiological state 

 of these cells in albinos is produced by the direct action of a hor- 

 monal substance and not by influences mediated through the 

 nervous system inasmuch as nervous connections are completely 

 severed, and it would be difficult to conceive of their reestablish- 

 ment by the time these changes are manifested. 



46 (1421) 



On the effects of ablation of the epithelial hypophysis on the other 

 endocrine glands. 



By P. E. Smith (by invitation). 



[From the Anatomical Laboratory, University of California.] 



When the epithelial hypophysis is ablated in early embryonic 

 stages in the frog, the resulting larvae suffer in a characterisic way 

 from defects in their pigment system. An equally definite set of 

 alterations is produced in the other glands of internal secretion. 

 Both Allen and the writer have reported the underdevelopment of 

 the thyroid gland to which may in turn be attributed the failure 

 of metamorphosis in these larvae. The posterior lobe of the hypo- 



