THE VITAMINES IN THE ANIMAL KINGDOM 105 



hydropericardium in pigeons. McCarrison (290) attributes the 

 edema to the enlargement of the suprarenals. 



Endocrine glands. The first investigations in this direction were 

 made by Funk and Douglas (291). The findings in pigeons showed 

 that the thymus glands disappear; this was also noted by R. R. 

 Williams and Crowell (292). The behaviour of this gland in birds 

 was then investigated further by McCarrison (293). Funk and 

 Douglas made a histological investigation of pituitary, adrenals, 



FIG. 18. FATTY DEGENERATION OF SCIATIC NERVE IN CHICKEN BERIBERI 



ovaiy, testicle, kidney, liver, pancreas and spleen. In all these 

 organs, definite signs of degeneration were noted. The investigation 

 of thyroid in greater detail was made by Douglas (294) who observed 

 carefully the great variations and the tendency of the colloids to 

 disappear from the vesicles. McCarrison (295) studied the influence 

 on the thyroid of food poor in vitamine, and found that the size of the 

 gland, as well as the weight, decreased. The study of the endocrine 

 glands of pigeons was then undertaken by the same worker (296) 

 who largely corroborated the work of Funk and Douglas, and found 



