80 THE INTERNAL SECRETIONS 1920 



munity of the animals against B. pyocyaneus. It is, 

 however, well known that any operation may have the 

 same influence in diminishing the natural resistance of 

 the body. Sajous (2), Lorand (3), Miiller (4, 5), 

 Marbe (6, 7, 8, 9, 10, 11) , and Palazzo (12) , have found 

 that the thyroid gland plays an important part in im- 

 munology and that removal of the thyroid in animals 

 diminishes the opsonic index against microbes. 



There are, however, many authors who do not con- 

 firm these views. Fassin (13, 14, 15), did not observe 

 any difference in the amount of complement before and 

 after thyroidectomy in animals. She stated, however, 

 that experimental injections of thyroid extract or its 

 oral ingestion in man increases the amount of comple- 

 ment. This last statement has been confirmed by 

 Muller (5), Bianchi Mariotti (16), and Frouin (17) ; 

 and Fjeldstad (18) never detected a difference be- 

 tween the formation of antibodies in animals with and 

 without a thyroid gland. Frouin even goes further, 

 for he states that animals from whom the thyroid is 

 removed, give, when immunized against tetanus, a 

 much higher antitoxic serum than the normal control 

 animals. Very recently these experiments have been 

 repeated by Garribaldi (19, 20) . He found that in rab- 

 bits, which were injected with corpuscles of the sheep, 

 the titration of the hemolytic antiserum was higher 

 when the thyroid previously had been removed, than in 

 normal animals. He also stated that the serum of 

 thyroidectomized dogs had a higher amount of hetero- 

 hemolysin than the serum of normal animals. 



Stepanoff (21) , has proved that the resistance of the 

 body to infections is largely increased by the adminis- 

 tration of thyroid extract. Parhon (22), was able to 

 prove that thyroid preparations may prevent sponta- 

 neous infections in birds and other animals and that 

 they even may play an important part in cholera pre- 

 vention in men. Koopman (23), observed two rabbits 



