Chemico-Fujicfional Integration 119 



cited. 



Concerning the effects of removal of tlie tliyroid appa- 

 ratus he says : 



"The most acute symptoms are exliihited hy carnivora such as 

 dogs^ cats, foxes^ and wolves (Vincent), and tlie young of lierhi- 

 vora (v. Eiselsberg, Sutherland Simpson) and are of a nervous 

 nature. . . . Some species exliibit no symptoms whatever — at 

 least when the operation is })erfornu'd on the adult. Horslcy 

 states that this is the case with birds and rabbits; but according 

 to Gley, the latter are affected if care is taken to find and re- 

 move all four parathyroids, and Dp3'on and ,Jouty obtained tyi)ical 

 tetany in hens which had been parathyroidectomized. . . . Ac- 

 cording to Vincent and Jolly badgers are totally unaffected by 

 complete removal of both thyroids and parathyroids." ^ 



From the anatomical characteristics of the organs, 

 and from tlie known effectiveness of minute portions of 

 them, such statements as the last must be taken with re- 

 serve. Although these results show by their diversity that 

 an enormous amount of study remains to be done on the 

 comparative side, they leave no question that the secretion 

 of the thyroid af)paratus is important for the general 

 health and equilibrium of most animals in which it occurs. 

 The measure of tliis importance in the eyes of some authori- 

 ties is seen in sucli a statement as, "No cell anywhere in the 

 body can reach morphological perfection without thyroid 

 stimulus." * 



The Internal Secretion of the Duodenal Mucous Mcnihraue 



We now pass to an examination of thi- effects of the 

 internal secretion of the duodenal nuicons lucnibrafu". 'I'his 

 particular secretion is selected for the n-asons that it is, 

 according to Bayliss, one of its discoverers, "the most 

 typical of all the chemical messengers''; that it was om- of 

 the first to be investigated; and that it is one of the Uw 

 which have been isolated as definite substances. 



