494 BULLETIN OK THE BUREAU OF FISHERIES. 



It would thus appear that water is not the exclusive carrier of the etiological agent 

 of goiter, but the giving of large quantities of water to experimental animals in a goi- 

 trous region, favors the development of goiter when the agent may find entry in some 

 other way. These observations tend to increase the significance of the finding of nema- 

 todes or other possible carriers in connection with the production of experimental 

 goiter in animals. 



McCarrison (1909) produced experimental goiter in human beings by giving them 

 residues from the filtered water of Kashrote, where goiter prevails to the extent of 

 45 per cent of the total population. Experiments were carried out in the nongoitrous 

 village of Barmis so controlled that they were provided with water for drinking, bathing, 

 and other cleansing purposes from the Barmis spring, which is nongoiter producing, 

 but which, as an added precaution, was boiled. Their diet was chiefly vegetable. Of 13 

 individuals whoconsumed the untreated residue of the goiter-producing water of Kashrote 

 4 developed a noticeable swelling of the thyroid gland, while 2 others showed an increase 

 in size of the organ, demonstrable by measurement and evident to the touch. In three 

 cases the enlargement was produced early, making its appearance on the thirteenth to the 

 fourteenth day of the experiment. It was not great nor did it appear under the 

 conditions of the experiment to be progressive. Of eight individuals who under the 

 same conditions consumed the boiled residue of the goiter-producing water of Kashrote 

 none developed any swelling of the thyroid gland, and this although three were 

 individuals peculiarly likely to respond to goitrous influences. McCarrison therefore 

 concluded (i) that goiter is due to matter in suspension in the water; (2) that goiter 

 is not due to the mineral but to the living part of the suspended matter; in other words, 

 to a living organism of the disease; (3) that the incubation period of experimentally 

 produced goiter is 13 to 15 days. 



An experiment of similar import is reported by Breitner (1912) which relates to a 

 family of father, mother, and seven children who, coming from a goiter-free region, 

 drank the water from a goitrous well with the result that all nine individuals developed 

 a great increase in the circumference of the neck with palpable tumors. Upon the 

 advice of Breitner they boiled the water from this source and after a period of four weeks 

 a distinct diminution of the thyroid tumors occurred, but later they disregarded this 

 advice with the result that the thyroid enlargement again progressed. From this well 

 Breitner carried out experiments with rats with the result that in 19 rats 2 developed 

 large visible struma, 2 thyroids two and one-half times as large as normal, and 4 showed 

 microscopic diffuse enlargement of the thyroid, whereas 20 controls showed no 

 enlargement. 



The literature contains many accounts of human beings going from nongoitrous 

 regions into localities in which goiter is endemic and there quickly acquiring the disease. 

 One of the oldest and most striking of those given is that reported by Hancke in 1819, 

 in which all but 70 young men of a battalion of 300 in the course of a year developed 

 such pronounced goiter that it was found necessary to remove the regiment to a non- 

 goitrous region, where those who were not too far advanced recovered, the enlargement 

 of the thyroid disappearing. Hancke states that in the infected region referred to 



