32 PHYSIOLOGY CHAP. 



thyroid and the thymus, more successful. Gley (1894) demon- 

 strated the fallacy of this theory. 



Attempts to demonstrate a functional relation between the 

 thyroid and the glandular portion of the cerebral hypophysis or 

 pituitary gland succeeded better. These results will be referred 

 to below, in their proper connection. 



It is to Gley (1892) that we must ascribe the merit of having 

 pointed out the importance of the parathyroid glands, previously 

 discovered by Sandstrom. Along with the thyroids, he excised 

 the two little glands of Sandstrom in rabbits, which died, under 

 these circumstances, with symptoms of tetany, even \vhen the 

 removal of the parathyroids was effected a month later than that 

 of the thyroids. But when the parathyroids alone were excised 

 in rabbits, no pathological symptoms appeared. He concluded 

 that the parathyroids acquire great importance only after the 

 extirpation of the thyroids probably because they have the 

 function of vicariously replacing them. In confirmation of his 

 hypothesis, Gley observed that the parathyroids become hyper- 

 trophic a month after the excision of the thyroids, and exhibit 

 modifications by which their structure approximates to that of 

 the thyroids, as if they were embryonic thyroids intended to 

 supplement any functional insufficiency of the adult gland. 



Subsequently, in collaboration with Phisalix (1893), he per- 

 formed the same experiment on dogs, and came to the conclusion 

 that these animals also survived the complete extirpation of the 

 thyroids, when precautions were taken to spare the parathyroids 

 and leave them in situ; while symptoms of tetany inevitably 

 supervened, when the latter were also extirpated. Ablation of 

 the parathyroids alone did not, according to Gley, produce morbid 

 sequelae. This confirmed his theory of the supplementary function 

 of the parathyroids. 



His conclusions were, however, contested by Moussu (1893), 

 Hofmeister (1894), and particularly by Vassale and Generali 

 (1896). These authors disputed Gley's observations as to the 

 structural modifications of the parathyroids after removal of 

 the thyroids. But as Eouxeau (1896) confirmed the fact of the 

 conspicuous increase of the parathyroids after thyroidectomy, and 

 the innocuous effects of simple parathyroidectomy, many people 

 adopted Gley's view of the functional interchanges between the 

 thyroid and parathyroid glands. 



Gley's hypothesis was first shaken by the accurate work of 

 Vassale and Generali (1896), which showed that a specific 

 functional importance distinct from, and even greater than that 

 of the thyroids must be granted to the parathyroid glands. These 

 authors excised the parathyroids only on numerous dogs and cats, 

 and found that they succumbed rapidly, the cats usually in 5, the 

 dogs in 3 to 4 days after the operation, i.e. the more rapidly in 



