THE THYROID GLAND AND THE ADRENALS. 149 



which eliminates them from the list of poisons and indicates 

 a direct relationship with a physiological function. In the 

 second place, it is well known that the symptoms that occur 

 after removal of the thyroid in animals may be arrested for a 

 time by injections of thyroid extract, while grafting or trans- 

 planting of a gland into the peritoneum, the abdominal wall, 

 or elsewhere may arrest them completely. Christiani, 6 in a 

 series of experiments on reptiles and mammalia, found that 

 properly transplanted thyroids continued their functions, and 

 that they preserved their morphological characters without 

 showing any tendency to atrophy. Von Erlenden 7 ascertained 

 that such glands continued to produce their colloid material 

 and formed new vascular connections, all facts which SchifE, 

 Horsley, von Eiselsberg, Canizzaro, and many others had al- 

 ready noted. Christiani also 8 ascertained, by means of micro- 

 scopical examinations of fragments of transplanted organs, 

 repeated at short intervals, that vascular regeneration of the 

 gland occupied three months. 



Again several experimenters have successfully performed 

 transplantations in carnivorous animals, cats, dogs, etc., 

 which, we have seen, often die after thyroidectomy. How could 

 we account for the absence of even marked symptoms in these 

 animals during the prevascular period i.e., that ensuing be- 

 tween the date of transplantation and the third month if the 

 thyroid had for its mission to destroy toxics in situ? If the 

 function of the organ is to destroy these bodies within its own 

 structures, can we reasonably expect the insignificant quantity 

 of blood which then courses through the transplanted organ 

 to satisfy the needs of the function? In order to carry it on 

 satisfactorily the entire blood would have to course through 

 the grafted thyroid, whereas even when the organ is in its 

 normal position in the neck, only a comparatively small pro- 

 portion of the blood of the organism passes through it not- 

 withstanding its large vascular supply. On the other hand, 

 we can easily understand how immediate benefit could be ob- 



8 Christiani: Revue M6dicale de la Suisse Romande, Dec. 20, 1900. 



7 Von Erlenden: Centralblatt fur d. Grenzgebiete der Medicin und Chirurgie, 

 Nov., 1899. 



8 Christian! : Archives de Physiologie, Jan., 1895. 



