458 KELSON W. JANNEY 



Transmission of the disease through drinking water is a thoroughly 

 established /act. The disease is not produced by dissolved chemicals in 

 the water, nor by radioactivity. 



The hydrotelluric theory of Bircher, attributing the disease to deposits 

 in certain geologic strata, also the Plutonian Theory of Kepin, are dis- 

 proven. 



The etiologic agent in water collects in the sediment and may be 

 destroyed by boiling, partially removed by nitration ; decreased or caused 

 to disappear by general hygienation of the water supply. 



Theory of direct contagion: There is considerable evidence, but 

 nearly all of indirect nature, that intimate contact in dwellings and with 

 fomites of affected individuals may cause the disease. 



The Bacterial Theory of McCarrison is supported by endemiological, 

 epidemiological, clinical and experimental evidence of importance. It 

 offers a reasonable explanation of the known etiologic data in production 

 of the disease; the influence of the water supply, close contact, the con- 

 formation of the soil, etc. It traces the source of the causal agent to animal 

 and human excrement, particularly to intestinal bacteria and their toxins, 

 but further corroboration and elaboration are necessary before general 

 acceptance of this theory can be expected. 



Pathology 



The Thyroid Gland. The Thyroid Gland of Endemic Cretinism shows 

 no essential pathological lesions differing from those exhibited by this 

 organ in hypothyroidism. Though all grades of thyroid degeneration 

 may be present, the pathological changes in the gland fail to show as defi- 

 nite parallelism with the clinical symptoms as seen by sporadic hypothy- 

 roidism. This is particularly exemplified by endemic deaf-mutes and 

 idiots who on. postmortem may occasionally possess glands with only 

 insignificant lesions. The most acceptable explanation for this discrepan- 

 cy is the theory that the cretinic degeneration is due to a toxemia affecting 

 directly various organs in addition to the thyroid. The pathological 

 changes may be hypertrophic (goiter) or atrophic in type. 



a. Pathogenesis of Goiter. Thyroid hypertrophy (endemic goiter) 

 may be the only demonstrable manifestation of the Cretinic Degeneration, 

 (loiter is much more prevalent among endemic than sporadic cretins, 

 Kwald reporting thyroid hypertrophy in 62 per cent of endemic cretins. 

 According to the chemopathologic standpoint adopted by a number of 

 modern investigators of thyroid disease, all forms of thyroid hyperplasia 

 are essentially due to toxic injury and consequent subfunctionation or in- 

 creased need for the thyroid hormone over and above the output capacity of 

 a ji-iven normal gland. In this regard Marine and Lenhart (g) remark: 



